One is a textbook because it's Dh's, but the rest are all of my personal books I bought from Barnes and Noble. My bookshelves are getting too full so I was trying to sell them. I will probably just end up giving some to my niece and donating the rest to Goodwill. We usually donate a pile of things every two months to Goodwill. I might look on Ebay today and see if I could sell them on there, but I'm not getting my hopes up.
Amazon has a textbook trade-in system. That's what we used for most of our textbooks during and after college. You could try that. I'm not sure if they will take loose-leaf books or not.