Okay, so I want an iPod but I can't afford a new one. Sucks for me.

I'm thinking of buying a used one from a member on here. However, I remember reading something about the software and the iPod itself only being able to be used with one computer. The original that it was installed on.

If I buy a used iPod, how can I be sure that my computer will recognize it? I'd hate to spend over $100 on something I can't use. Thanks in advance.