We're all eligible to receive three free credit reports every year (one from each of the national credit bureaus), but credit scores typically come at a cost of $15.95 per score. There are some unreliable sites out there that may claim to have access to free credit scores, but generally those sites aren't trustworthy.
MyFICO.com is actually a division of Fair Issac, the company that calculates consumer credit ratings for lenders, and is a legitimate source of credit information. They have a promotion going on that includes a free trial of their services, which comes with two free Equifax FICO scores and credit reports. If you cancel the 30-day trial immediately after receiving your free reports and score, you won't have to worry about forgetting to cancel and having to pay for a service that you may not want. The option to cancel online makes it easy.