(MONEY Magazine) – Since credit scores went public two years ago, ads for credit services--three-in-one bureau reports, score simulators, fraud alerts and ID-theft insurance--have reached a fever pitch, especially online. But will any of the tools help you get a loan, pay a lower rate or protect your personal financial information? We sifted through dozens of websites, many new this year, to find the best.

Getting your credit history. A score based on your credit history helps to determine your insurance premiums and loan rates. Toyota, for example, recently announced that you need a FICO score (which most lenders use to determine borrowers' creditworthiness) of 660 or more to qualify for 0% financing. Lenders look at reports from all three credit bureaus; to know where you stand, you should do the same. There are two ways to go: the all-in-one report--we like the $44.85 one from www.truecredit.com--or the individual reports from Experian (800-397-3742; www.experian.com) and TransUnion (800-916-8800; www.transunion.com) for about $9 each. You'll also need the Equifax report (800-685-1111; www.equifax.com), but rather than sending in your $9 for the report alone, spend $12.95 to get both the Equifax report and your FICO score (plus tips on improving it) from Fair Isaac's ScorePower. It's available on the Equifax site and at www.myfico.com. The MyFICO Simulator on the latter site will also give you an idea of what mortgage rate you'll qualify for based on your score. (Other debts, the value of the home and your salary come into play as well.)

At www.knowyourloanrate.com, you can get a rate prediction that takes your debt-to-income ratio into account for $29.95. And if you're buying insurance, you can now get your auto and homeowners insurance risk scores for $12.95 each at www.choicetrust.com.

IMPROVING YOUR CREDIT SCORE. The best ways to raise your score are free: Pay bills on time, pay down debt and keep all balances well below your credit limit. If you need more help, E-Loan's new $29.95 Credit Score Monitoring Service will suggest specific moves, such as which of your credit-card balances you should pay down first to boost your score quickly.

PROTECTING YOUR IDENTITY. Again, the smartest steps are free: Shred documents with your personal information and opt out of prescreened credit-card offers (call the Federal Trade Commission at 888-5-OPTOUT). If you even suspect ID fraud, you have the right to get your credit report for free. Also ask the bureaus to put a credit alert in your file.

Services that monitor your credit reports "won't help prevent your information from getting into the hands of a thief," says Joanna Crane, manager of the FTC's ID Theft Program. "But [they] can narrow the amount of time it takes you to discover the crimes." If you're worried or have been a victim of ID theft, you may want to subscribe. Equifax Credit Watch (www.equifax.com) is the best value. For $69.95, you get unlimited online access to your credit report, e-mail notification of changes within 24 hours, your FICO score and a rate predictor. --Maya Jackson