WHEN THE WORLD OF MONEY FEELS AS IF IT’S MOVING at 1,000 miles an hour (as it does now), and new, sometimes contradictory information never seems to stop coming (as it does now), the ability to discern what’s noise, what matters, and what to do about it is invaluable. That’s probably why you picked up this magazine. Good move.

The next step, combining the lessons you learn here with the latest data and details of your personal situation so that you can make sound money decisions—that’s a task for software, not scribes. And that’s what great websites let you do. But which ones? To answer that question, a three-person team of MONEY writers spent two months quizzing experts and test-driving sites and mobile applications that focus on investing, real estate, spending, health, jobs, and more. (We didn’t assess sites that deliver primarily news and information, such as WSJ.com or our own CNNMoney.com.) Some are revolutionary—such as one that tells you in the store whether there’s a better price to be had on an item you’re about to buy—and some were early forces on the web—such as Morningstar.com—that still can’t be beat when you face a complex issue. The result: a short list of the best ways to navigate today’s swirling financial seas.

YOUR PORTFOLIO

TIP: Before using a retirement calculator, gather your account statements, mortgage info, and your Social Security estimate from SOCIALSECURITY.GOV.

1. Do I need to save more for retirement?

BEST SITE: BASIC.ESPLANNER.COM

With the markets bouncing around so much, you may have checked some online calculators to see if you need to shovel in more cash. But many of those tools are flawed, argues Boston University economist Laurence Kotlikoff, the brain behind ESPlanner. For a start, they often ask you to guess how much of your pre-retirement income you’ll want to live on. “Who knows what percentage you should choose? Is it 80%? 75%?” asks Kotlikoff.

ESPlannerBASIC skips such imponderables. It asks what you earn, what you spend, and how your financial obligations will change over time. (For example, when will your youngest kid graduate?) It then assumes that you’ll want your family to maintain the same living standard from today on, and figures out how much you can afford to spend, plus how much life insurance you’ll need. Because ESPlanner asks such detailed questions, it will take at least 30 minutes to complete. But it’s the most in-depth plan you can get for free.

CAVEAT: ESPlannerBASIC saves your data for only 24 hours. Set aside an evening when you’ll have time to complete the process.

TRY THIS TOO: For a quick review of how you’re doing, go to CNNMONEY.COM/TOOLS and “Check Your Financial Health.”

2. Do I have the right mix of investments?

BEST SITE: MORNINGSTAR.COM

The first, critical step is to be sure you have a complete picture of what you really own, and Morningstar’s Instant X-Ray is the best tool we’ve ever found for that. Just type in the investments you hold, and you’ll see how much of your total portfolio is in stocks, bonds, and cash, as well as how much you hold in each sector, world region, and stock category, such as large growth or small value. You may be surprised at what you see. You are likely to have a lot more of your portfolio in equities than you did a year ago, when stock values were way down. Or the mutual funds you own may have changed their tactics. “You might want to have just 20% in cash, but there are managers who might go 50% into cash,” says Maryland financial planner J. Patrick Collins Jr.

COOLEST FEATURE: You’ll also see the total fund fees you’re paying and whether that’s relatively cheap or expensive.

TRY THIS TOO: To estimate your ideal percentage in stocks, a simple guide is to subtract your age from 110. For a more refined view, take a risk-tolerance test from FinaMetrica, which through April is offering MONEY readers a free report at RISKPROFILING.COM/MONEY.

3 Is my portfolio too risky?

BEST SITE: PORTFOLIOMONKEY.COM

Tell this site what you hold, and it estimates how much volatility you can expect your investments to deliver, as well as an expected return. As the site itself warns, such projections should be taken “with a grain of salt”—we’d say a lump. But Portfolio Monkey’s calculations are built on well-known research showing that factors like company size, valuation, and past volatility help predict a stock’s performance.

Use the site to supplement your usual stock analysis. For example, Microsoft and Dell may seem similar in that they are both blue-chip tech firms, but Portfolio Monkey says Dell is notably more volatile.

COOLEST FEATURE: The Probability Analyzer shows how much your portfolio could grow—or shrink.

TRY THIS TOO: MORNINGSTAR.COM for a snapshot of a stock’s fundamentals.

4 I like growth (or value) stocks. How do I find my next pick?

BEST SITE: FINANCE.GOOGLE.COM

Plenty of free sites help you screen stocks by criteria like earnings growth or P/E ratios. But Google’s Stock Screen tool makes the process intuitive. Want to see only stocks with P/Es at the low end of the range? A bar chart showing the current distribution of P/Es in the market is built right into the selection tool (see above). Just move a pair of sliders along the chart to focus on the part of the market you want to see.

COOLEST FEATURE: For a unique indicator of consumer and market sentiment, check Google Domestic Trends—it shows you how often Google users searched industry-related keywords. Searches on luxury goods are way down since 2006.

TRY THIS TOO: GRAHAMINVESTOR.COM has preset screens based on the value-investing philosophy of Ben Graham. It’s run as a hobby by an IT guy who’s also a Graham fan.

Google’s screener lets you see the whole market as you sort.*

NOTE: *The screen shots of websites in this story have been edited to highlight key features.

FOUR GREAT iPHONE APPS

Most of the best handheld money apps are still iPhone-only.

Where’s the nearest ATM that won’t cost an arm and a leg?

APP: ATM HUNTER

WHY IT’S GREAT: This app from MasterCard lets you search for ATMs based on your bank, surcharges, and other features. You can look for ATMs where you are or at an address you are headed to.

COST: Free

How do I know the price I’m looking at in a store is a good deal?

APP: REDLASER

WHY IT’S GREAT: This app scans any bar code and uses Google Product Search and TheFind.com to locate the best price. At Best Buy, MONEY saw two Blu-ray movies for $29.99 each; RedLaser found them for $19.99 at Walmart.com. Best Buy matched the price on the spot. Result: a $20 savings.

COST: $1.99

That house I’m driving past is fabulous! What is it listed for?

APP: REALTOR.COM

WHY IT’S GREAT: It uses GPS to produce a map of properties for sale and open houses near your current location, which you can refine according to distance, size of house, price range, and more.

COST: Free

I know I’m going to lose this receipt—and I need it for tax purposes. Help!

APP: IXPENSEIT

WHY IT’S GREAT: It enables you to quickly punch in receipt info, even letting you take pictures of those scraps of paper and store them digitally.

COST: Free for the Lite version (stores up to 200 records); $4.99 for the full version (no record limit)

YOUR WALLET

TIP: Before you pick a new bank, make sure BANKRATE.COM’s Safe & Sound ratings give it at least three stars.

5 Is it time to dump my rewards card for a better one?

BEST SITE: NERDWALLET.COM

Now that a new law makes it harder for card issuers to charge tricky fees, some are getting less generous with the rewards they dole out. This site, founded by a Stanford-educated hedge fund analyst, combs through 400 cards to find the best one for you. Enter the amount you generally charge each month, what kinds of things you buy, and your estimated credit score. Presto: a list of cards that will maximize your rewards. You can also search for the best low-rate or balance-transfer cards.

COOLEST FEATURE: Filter results by the kind of rewards you prefer—say, airline miles or cash back.

TRY THIS TOO: The credit card comparison tool at BILLSHRINK.COM. Its database doesn’t include as many cards, but it lets you sort results by tons of features, such as 24-hour customer service.

6 How can I cut my spending so that I can save more?

BEST SITE: MINT.COM

With salaries stagnating, the pressure to create and stick to a real budget is on. Dozens of sites have cropped up lately to help you do just that. But Mint.com (recently purchased by tax-prep giant Intuit) is by far the easiest to use and most feature-packed. Sync your bank, credit card, and investment accounts with the site—it takes only a couple of minutes—and start following the money. Mint tracks every noncash expenditure (“I dropped how much at Whole Foods?”) and summarizes your spending in categories, such as food or utilities.

COOLEST FEATURE: With one click, turn your average spending into a monthly budget—and then adjust amounts in each category until you find a balance you can live with.

TRY THIS TOO: If you want to budget plus pay bills through just one site, YODLEE.COM’s MoneyCenter may be better for you.

7 How good is my credit?

BEST SITE: CREDIT.COM

Banks today want pristine credit, and just a few points can make the difference between a good and a great rate on a loan, says Curtis Arnold of CardRatings.com. For a quick sense of where you stand (for free!), you can’t beat Credit.com. Click on the Credit Report Card and answer a few questions. The site will pull your credit report (a “soft” inquiry that doesn’t hurt your rating) and give you a grade of A+ through F on each relevant factor, plus tips on how to improve. A MONEY staffer learned she can’t score A+ across the board unless she proves she can handle another loan.

CAVEAT: You don’t get your exact credit score, just a range where you fall. (If you want a hard number, buy it for $15 at MYFICO.COM.)

TRY THIS TOO: CREDITKARMA.COM lets you see how changing one factor might affect your score.

Surprise! Taking out a new loan may lift this credit score.

8 How can I find a better-paying savings account?

BEST SITE: BILLSHRINK.COM

With the average bank savings account yielding a pathetic 0.24%, it’s no wonder you’re on the hunt for a better deal. But interest rates aren’t the only thing to consider: “You need to factor in fees,” says Schwark Satyavolu, co-founder of BillShrink. Type in your current balance, the features you want (such as online bill paying or ATM access), and other info, and this innovative site coughs up the savings accounts and CDs that will leave you with the most dough in your pocket.

COOLEST FEATURE: BillShrink can send you alerts when a better rate becomes available.

CAVEAT: The site gathers data from 54 banks and credit unions around the country, including most of the biggies. But good ones may slip through the cracks.

TRY THIS TOO: Visit BANKRATE.COM, the data supplier for our savings charts (see page 114), which has a more comprehensive list of the best rates in the U.S. But you’ll have to do the legwork on fees yourself.

Learn your potential long-term payoff after fees.

DON’T TRY TO DO THIS ONLINE

Even good sites may have certain tools that aren’t so hot. Some sites may make you poorer. And sometimes the problem is you.

WASTE OF TIME

RISK LEVEL

DON’T Think that Zillow.com tells you what your house is really worth.

The “Zestimates” on this popular real estate site are based heavily on sales prices of comparable homes. So unless there’s been lots of activity in your ‘hood lately—unlikely these days—the value may not be very accurate.

INSTEAD

Call an appraiser to size up your property in person.

DON’T Limit your search to job-posting sites such as CareerBuilder.com.

Employers filled only 4% of their open positions through CareerBuilder (one of the nation’s largest such sites) in 2008, according to staffing strategy firm CareerXroads.

INSTEAD

Network: 27% of external hires are found through referrals.

DON’T Get price quotes on a car through Edmunds.com.

This site is great for car reviews, but try to get a quote and you’ll be pelted with dozens of e-mails from car dealers for months—and almost none of them will include a price.

INSTEAD

Ask a local dealer for a quote, then call around to see if any other dealers can beat it.

WASTE OF MONEY

RISK LEVEL

DON’T Order your credit report from freecreditreport.com.

Yeah, its jingles are catchy. But if you’re not careful, this Experian-owned site isn’t free at all: It starts with a one-week trial, then automatically signs you up for $14.95-a-month credit monitoring.

INSTEAD

For a report that really is free, go to annualcreditreport.com.

DON’T Take investing advice from Yahoo Finance message boards.

Using a stock tip from “MSFTMan47″ may cost you dearly. The discussion is usually more hype than substance.

INSTEAD

Check out the forum Bogleheads.org. Many participants are investing pros who dish out sensible, low-cost buy-and-hold advice.

DON’T Buy a car sight unseen on eBay.

Online auctions can be great for getting a deal on small items such as vases. But the consequences of making a bad choice are much greater for big-ticket purchases.

INSTEAD

Most eBay sellers will let you hire a local mechanic to check out the car in person. Do it.

DOWNRIGHT DANGEROUS

RISK LEVEL

DON’T Shop online in a coffee bar.

Buying stuff on a public Wi-Fi connection is like reading your credit card number out loud. Any snoop with the right tools can steal your info, says Javelin Research analyst Mark Schwanhausser.

INSTEAD

Wait until you’re on your home network. If you must shop on the go, use a mobile connection.

DON’T Let your kids get music and movies from peer-to-peer sites.

It’s usually illegal. And what might seem like a harmless download could give scammers access to files on your hard drive.

INSTEAD

Set up a prepaid “allowance” on the iTunes Store. You’ll pay around $1 a song, but you’ll be safe.

DON’T Give out account numbers or other personal info on just any site.

The site you’re visiting may be a legitimate store or bank. Or it may be a thief’s clever facsimile.

INSTEAD

Never visit a site via a link in a pop-up ad or e-mail message. Instead, type the web address of a trusted site directly into your browser.

YOUR HOME

TIP: Use Google Maps’ Street View tool to sneak a peek at a neighborhood you’re interested in.

9 Which neighborhood should I live in?

BEST SITE: NEIGHBORHOODSCOUT.COM

Narrow down your house hunt by clicking on the site’s Find tab. You’ll get an interactive map that lets you compare neighborhoods by factors such as crime rates, quality schools, or even whether the area is a good place for retirees. You can customize searches by home price and population density too. “It’s a good first place to start,” says West Palm Beach, Fla., real estate agent Jesse Bailey.

CAVEAT: The Find maps let you see how neighborhoods compare based on a custom score, but if you want the actual crime stats or school test scores for a neighborhood, you have to pay ($29.99 for one month).

COOLEST FEATURE: Enter an address in a neighborhood you like; the site will show you similar ones in another town.

TRY THIS TOO: To see if a house is near shops and restaurants, check WALKSCORE.COM.

Get a map showing how different neighborhoods compare.

10 Where can I find sellers ready to deal?

BEST SITE: TRULIA.COM

This big real estate site lets you zero in on homes whose sellers have cut prices recently—an indication they may be ready to jump at your offer—and instantly tells you how far they’ve come down. A host of such well-designed tools distinguishes Trulia from worthy competitors Zillow.com and Realtor.com. (No harm checking them all, though; their lists overlap but aren’t identical.) Another great Trulia tool: Heat Maps, which display average list and sale prices within zip codes.

COOLEST FEATURE: SNAPSHOT.TRULIA.COM puts a neat visual twist on the usual listings. Move a slider to select homes by price or their time on the market; their photos pop up on a map. It’s a bit hypnotic, actually.

TRY THIS TOO: FORSALEBYOWNER.COM for listings that big sites won’t have.

11 Should I hire a contractor?

BEST SITE: DIYORNOT.COM

Whether you’re sprucing up the house to sell it faster or you just want a nicer kitchen, this site helps you compare the time and cost of doing a project yourself vs. hiring a local contractor. It’s run by Gene and Katie Hamilton, who have written 20 books on remodeling; they collect data from retailers and contractor price lists. You’ll find, for example, that in Chicago it’s $1,218 cheaper to install your own kitchen cabinets than to have a pro do the job.

CAVEAT: No website can tell you whether you are competent to install those cabinets. Consult your spouse.

TRY THIS TOO: DOITYOURSELF.COM gives step-by-step instructions on how to complete hundreds of home projects, from repairing a noisy air conditioner to shingling a roof.

YOUR HEALTH/YOUR JOB

TIP: Put a link to your public LinkedIn profile on your Facebook page. A social connection may be a job connection too.

12 Who are the best doctors in my network?

BEST SITE: VITALS.COM

Now that many health insurers are giving stingier reimbursements to patients who venture out of network, finding a great doctor who’s in your plan is key to keeping costs down. You need Vitals—a comprehensive physician-rating site that can show you only doctors who are covered by your health plan. It tells you their education, board certifications, work backgrounds, and patient ratings.

COOLEST FEATURE: Sick and not sure what kind of doctor you need? Input your symptoms and Vitals will guide you to relevant specialists near you.

TRY THIS TOO: PRICEDOC.COM, a new site that shows you what specific doctors around the country charge for various procedures.

13 Which hospital should I go to?

BEST SITE: HEALTHGRADES.COM

Click on “hospitals” and enter your location and procedure. HealthGrades will rank the quality of hospitals near you, showing how often patients there had major complications following surgery.

COOLEST FEATURE: You can see which hospitals have advanced technology, such as robotic arms for surgery.

TRY THIS TOO: WHYNOTTHEBEST.ORG, run by a private foundation, gives similar info.

Find out how a hospital performs before you schedule.

14 How can I find my next job?

BEST SITE: LINKEDIN.COM

You probably already belong to this 55 million–member networking site, but chances are you could be using it more effectively, says Colorado job-search coach Vicki Brackett. Fill out your profile fully. Make sure it’s publicly available. Add keywords that reflect your skills; borrow phrases from job descriptions to help recruiters find you. And join LinkedIn groups in your industry.

COOLEST FEATURE: You can search your own network to see who has connections to a company that’s hiring.

TRY THIS TOO: For job listings, go to INDEED.COM, which pulls together ads from multiple sites.

15 How do I keep my skills sharp?

BEST SITE: ITUNES U

With the job market still sluggish, staying current in your field—or adding new skills—is especially important. Enter iTunes U. Not technically a website but rather a destination inside Apple’s iTunes Store, it lets you download free materials ranging from finance lectures at Yale to interviews with Wharton faculty members.

CAVEAT: None of the lectures will earn you any credits—but for mid-career folks, ideas can be as valuable as credentials.

TRY THIS TOO: ACADEMICEARTH.ORG has a smaller selection, but it’s focused on top schools.

YOUR PURCHASES

TIP: Type in your payment and shipping info via BILLEO.COM and you won’t have to reenter it every time you shop online.

16 What’s the lowest price I can finagle on this car?

BEST SITE: TRUECAR.COM

With auto rebates getting rarer and prices starting to rise, you need all the negotiating ammo you can get. It’s not hard to find a site that divulges the dealer invoice price for various models. But TrueCar tells you something that’s even more helpful: exactly what other buyers in your area recently paid for the model you want. With that info—gathered from finance companies, insurers, dealers, and other sources—you can make short work of negotiating. TrueCar VP Jesse Toprak says the average user strikes a deal in 15 minutes or less.

COOLEST FEATURE: You’ll get a nifty graphic combining the breakdown of the dealer’s actual costs, the average price people are paying, and what’s considered a great vs. merely a good deal for that model.

TRY THIS TOO: The True Market Value tool at EDMUNDS.COM offers a slightly different take: Analysts adjust the data to reflect market conditions. It doesn’t give as much info as TrueCar does, however.

17 Where can I get the best deal on electronics or appliances?

BEST SITE: PRICEGRABBER.COM

To drum up sales, retailers have been offering lots of short-term bargains lately—making it tough to know you’re getting the lowest price at any given time. Zillions of sites out there can help you compare prices, but shopping engine expert Brian Smith loves PriceGrabber’s combo of usefulness and comprehensiveness. Enter the product you want and your zip code, and up pops a list of retailers that offer the best prices after taxes and shipping. MONEY recently found a Panasonic Viera 50-inch plasma TV for $700 at superstore TigerDirect.com; after factoring in $99 shipping, NewEgg.com was $80 cheaper.

COOLEST FEATURE: Want to pay no more than, say, $650? Set an alert naming that price. You’ll get an e-mail when a retailer hits it.

TRY THIS TOO: GOOGLE.COM/PRODUCTS, Google’s price-comparison tool. It lacks a price-alert feature but tracks some retailers PriceGrabber doesn’t.

Bingo: the lowest price after taxes and shipping

18 How can I pay less for everyday stuff like food?

BEST SITE: COUPONS.COM

People of all incomes are now using coupons; websites make downloading and printing them easy. You’ll generally find the best variety at Coupons.com. Recent deals: $2 off Aleve pain reliever, $1 off Kraft cheese.

COOLEST FEATURE: It can zap discounts right to your grocery store loyalty card.

TRY THIS TOO: SMARTSOURCE.COM is similar.

19 How can I save on my flight?

BEST SITE: KAYAK.COM

If you go to only one travel search site, make it Kayak. It ropes in not just the deals offered at such big online travel agents as Orbitz and Expedia but also those from dozens of other travel sites and airlines that many tools miss. A recent search for a spring flight from New York to Lima, for example, turned up one on Copa Airlines’ site that cost $30 less than the same flight on Orbitz.

COOLEST FEATURE: Kayak shares the deals its users have found on your route. If you can adjust your itinerary to match their dates, you may score the cheaper fare.

TRY THIS TOO: YAPTA.COM will track the price of your flight and e-mail you if it drops enough that rebooking makes sense, even with penalty fees.

20 Should I give to the charity that’s hitting me up?

BEST SITE: CHARITYNAVIGATOR.ORG

Whenever there’s a disaster such as the Haiti earthquake, scams aren’t far behind. This respected site can tell you if the charity soliciting you is (a) legit and (b) effective. Type its name in the search box and you’ll see a star rating. Three stars or above means the outfit has low overhead and is financially sound. (Three charities working in Haiti that score well: American Red Cross, Doctors Without Borders, and United Way of America.) No rating? The charity may not have 501(c)(3) status (so your donation may not be deductible), it may not really exist, or it may be too new or small for Charity Navigator to have rated.

COOLEST FEATURE: You get recommendations for higher-rated charities (if any) that do similar work to the one you’re checking out.

TRY THIS TOO: If you make your donations through NETWORKFORGOOD.ORG, you’ll be able to get all your deductible receipts in one place—and might cut your charities’ processing fees too.

Here’s where the money you donate will actually go.