Determine which of your textbooks are in prime selling condition, meaning they are gently used or like new. If the textbook looks worn, has visible damage or extensive highlighting, consider finding an alternative means to dispose of it or keep it.
Locate the ISBN numbers for each textbook you want to sell. For most textbooks, the ISBN is located on either the back cover above the bar code or on the publication page of the textbook. Most websites require ISBN numbers to identify and research each textbook you want to sell.
Decide how you want to sell your textbooks. Online auction websites, such as eBay, allow you, as the seller, to name your price for each book. Websites including Barnes & Noble or Amazon.com provide the opportunity to sell back your old textbooks for a fixed rate.
Consider how to ship your textbooks. Depending on the means you used to sell them, shipping methods will either be at your discretion or provided. Selling textbooks on an auction website like eBay requires you to incorporate shipping costs in your asking price. When selling textbooks to a vendor, such as through Barnes & Noble, the company typically sends you a free postage label via email. As the seller, you are then responsible for shipping the item either through the postal service or commercial shipping business.