Under the Fair Credit Reporting Act, you are entitled to one free credit report a year from each of the credit bureaus. Beyond that, if you have been turned down for credit, are unemployed, or live in Colorado, Georgia, Massachusetts, Maryland, New Jersey, or Vermont, you can get the reports at no charge. Otherwise, you will need to pay $10 or so for each one. The credit bureaus generally don't share information, so you need to make sure your record is correct at each one.
Mari J. Frank, an attorney in Laguna Niguel, California, who runs Identitytheft.org and is the author of The Identity Theft Survival Kit: A Complete Guide for Restoring Your Credit and Your Peace of Mind (Porpoise Press, $40, amazon.com), suggests also going to privacyrights.org to find out how to conduct a background check on yourself. "If an ID thief has gotten your driver's license or Social Security number, for example, you could have a criminal record in another state and not even know it," says Frank.