Visit www.abebooks.ca. You can sell as many textbooks as you want and the website will pay for the shipping costs. Abebooks will price the textbooks based on their condition and popularity. When you have enough textbooks to exceed the $15 (as of August 2010) payment threshold, you can send the books off and wait for your cheque.
Use www.amazon.ca. There, you can sell second hand books and textbooks to buyers who don't want to pay the full price of a new book. Amazon does charge commission on books you sell, but is a useful and convenient way of making some money out of old textbooks. Listings last for 60 days so you have plenty of time to get sales.
Visit www.ebay.ca. You can start an online auction or list them at a set price. Ebay allows you to sell items quickly, and your listing can last between one day and 30 days. You can also choose how you receive payment. The site gives sellers the option of using Paypal, which means you can transfer the money directly to your bank account.
Sell the books to a local second-hand book store. Selling your textbooks to a second-hand book store is an ideal way of getting rid of the books quickly, especially if you have a lot. Call the bookstore and check that they buy books before turning up.
Use textbookexchange.ca. Like Amazon, this site allows you to post used textbooks online for others to purchase. You can set your own price and, once someone has purchased your book, you are responsible for sending the book to the buyer. Payments are made through Paypal after the buyer has received the book.
Take advantage of your university's book exchange. Some universities, such as Toronto University, offer students a chance to sell used books to fellow students through a student-run website. Ask your school for details of similar schemes.