Update from my initial answer, and response to some other answers follows:
As time passes, the companies providing free credit scores will change. Don't "trust" that the company I referenced in my original answer will always be the "best" company to get your score from. After about 6 to 9 months, you should do more research to see who has the best deal.
That said, you should also be careful in presuming that your FICO scores are the determining factor a lender will use in giving you credit. The government needs to step in here and do the right thing, but I don't see it happening any time soon. Here's the problem. Credit advocacy groups fought hard to get you the right to pull your credit report for free, once per year, from each credit agency. But, and it's a big but (pun intended), you don't get your credit scores when you pull your credit history, yet your credit score is the most important piece of data.
Credit advocacy groups are now hard at work to allow you to get your credit scores, once per year, as well. But it appears that there are powerful forces to keep you from getting it, not the least of which are all the companies that will lose money by not being able to charge you for this information.
And here's the second big But. Did you know your FICO score isn't actually the score most lenders use in determining what you can qualify for in a mortgage!! They actually use different scoring systems, that are similar but not the same as FICO. Don't believe me? Then when you apply for a mortgage the next time, ask the lender when they are going to pull your credit, and go pull your own scores on the same day. I'll bet you 100 to 1 that the average and individual scores they get, won't be the same as the ones you get. And even more absurd, their scores will be noticeably lower than the ones you get.
Let's stop the nonsense. The federal government needs to give consumers ALL the information that ANY lending source might use to determine your credit worthiness. AND we should not have to pay for it. IT IS OUR INFORMATION they are charging us for. Next discussion - do you know what CLUE means? Did you know there are similar records kept about you, that other people access, to determine your insurance worthiness? Did you know you don't have access to that information at all? And how about your medical history - did you know they keep track of that too!!!!
Keep the faith!