Not most books but you can rent e-textbooks from them. They have a nookStudy application that is free for your computer. It doesn't work on e-readers though because it actually retains all of the illustrations. Find more info on that here: http://www.barnesandnoble.com/nookstudy/鈥?/a>Can you trade\sell e-books with barns and noble?
My understanding is no, e-books are a one shot deal.