Actually, you can access them online for your free one, I've used www.freecreditreport.com and refused the additional services. It seems to me there was a link on the .gov website. They do have to give you one free per year online. I used to have it book marked.... looked it up and its https://www.annualcreditreport.com/cra/index.jsp this one is snail mail. They do ask for a credit card for verification purposes (I believe you have to have had it for 3 years)

It really is important to check it. When we were buying our house there was a outstanding medical bill that was originally a whopping $1.57 from when the twins were born. The collection agency actually continued to keep it current. They don't care how much the unpaid bill is (creditors) just that there is one. When I contacted the credit agency holding the account they thought it was quite funny, I did not. With interest I owed them like $5.