Take your old textbooks to the college bookstore. Most campus bookstores have buy-back programs for students. Some bookstores only offer buy-backs at the end of the semester, and some will buy back books at any time. Contact your campus bookstore for details on its buy-back program. Many bookstores also have buy-back information on their websites. You can enter the book's name and author to get an estimated value of the book. Campus bookstores usually pay up to 50% of the cost of the book.
Sell your old college textbooks through an online auction site such as Half.com, Ebay or Amazon. These sites have templates available for most textbooks that will help you to list the details of your book in your posting. You must be a registered user in order to sell items on auction websites.
Post a notice on the dorm or campus bulletin board. Design a flier stating the name, author and edition of your textbook for sale. Include your asking price and contact information. Many students buy and sell college textbooks to each other.