The free ones on TV really arent free they are something that you have to sign up for but you can cancel it before you are actually charged anything so it is actually free but you have to give them a credit card number. I have done this before and it is totally safe.... But there also is a website that was set up by the 3 major credit bureau's (Equifax, TransUnion, and Experian) www.annualcreditreport.com...You can check it here for free once a year...Also some credit cards offer a service that allow you to get a monthly credit score and report for a small fee.
And yes when you check your own credit report it DOES NOT affect your score...BUT when a CREDITOR checks it it DOES reduce your score a few points....