I have been in school pursuing my medical assisting degree for about a year and a half now. I have had a lot of books that my school will buy back, but they do not offer much money. I have discovered amazon and they have been amazing. The process to sell your textbooks back to amazon is very simple. They allow you to print out a free shipping label, so there is no cost to ship your books back. Most of the time I get a pretty good amount for my books as well. I get much more in returning to Amazon then I do with my school and local book stores.
You can also buy textbooks from amazon. I purchased a text book a few months ago for $4 plus shipping! I think the whole order was about $7. My school was going to charge me $ 65 for the same book! So if your a student you need to look into the textbook buying and selling options from amazon. It really has made a big difference for me.