Sort of a 3-part/3-comment inquiry here.

1. I was playing around with several buyers websites and typed in up to a dozen cd's (80's/90's rock and smooth jazz) to test the waters and nothing came up. Is there only a certain selection of cd titles they are looking for?

2. Thinking this through I have to think: If you have burned the cd into your music library, as soon as you "sell" that cd you are a music pirate. Agreed?

3. How is this even legal? Then if you take it back even a step or two further, how is borrowing books or DVD's allowable without a royalty fee to the author? Is there a statuate of limitations or something?

I don't have an answer for 1.
2 - Yes. I submit that you don't even have to sell. If you play what you rightfully own in a manner that it is heard through the building where you work, you're a pirate if you don't pay fees. (You're probably on safe ground if the person in the next cubicle is the only one who can hear it.)
3 - The way I understand the laws, even lending a book or CD can be interpreted as piracy. However, I think that is unenforceable, and I'm not aware of anyone being sued or prosecuted for lending. There may not be a statute of limitations, but I think the industry realizes going after people for lending or even trading this material is counterproductive.

See page 22.

US Copyright Law

It's okay for you to sell your CDs. It is not illegal for a library to lend a CD since they do not gain anything commercially.