Paperbackswap.com is one of the greatest inventions ever! It is a great website to trade books. Any kind of book, cookbooks, children books, fiction, non-fiction, anything. You simply set up an account with a user name and password, post 10 books you are finished with and start shopping. The books you request are free to you, you pay nothing, not even shipping. If another person requests your book, you pay the shipping and mail it out to them, shipping is around $2.60 per book. Not bad at all.
The only downside is that you can only request books if you have credits, and you only get credits if people request your books. After you post your 10 books to start up your account, you get 2 free credits to get you started. I have never ran out of credits, but I can see how that might be a problem.
I highly recommend checking it out. You can look through the site and see what books are posted before you sign up. You might like it!