Book Buying Tips

1. Register for your classes as early as possible. Start researching courses as soon as you can, and solidify your schedule early. If you have to change classes at the last minute, it’ll be hard to escape high textbook prices.
2. Find out what books you’ll need for your classes. Go to the bookstore just to browse. Leave the wallet at home, but bring a pen and paper. Look for your classes and the new semester's required books. Ask the bookstore employees to assist you if needed. If your classes' book requirements are not in yet, inquire as to when they will be and come back on that date. You may also be able to get this information off the bookstore’s website or your classes’ web pages.
3. Write down the following information for each book: the name and volume/edition of the book, the name of the author, the book’s International Standard Book Number (ISBN), found on or near the barcode on the back of book, the price
4. Try to find the books in the library. Check the catalogs of your school library and the local public library. If you can’t find a book there, try to obtain the book via interlibrary loan. Depending on the library’s borrowing policies, you may be able to check out books for the whole semester or at least for as long as you’ll need them. You’ll want to get on this early, though, because supplies will be limited.
5. Search for books on the Internet. If you can’t get a book at the library, or if you’ll need to be able to keep a book or write in it, look for better prices online. Usually all you’ll need is the book’s ISBN. In the search box of your favorite search engine, enter only the ISBN number, without the dashes that separate the digits. You should come up with several exact matches; in the unlikely event that you don’t, try searching by title. Verify you have the correct book using the other information you wrote down.
6. Buy bundles. Bundled books save you money by allowing you to buy your books in one shrinkwrapped package, often at a discount.
7. Shop around online. Most likely just about any price you find online will be cheaper than the bookstore, but check as many sites as possible to find the cheapest possible book. Check out online auction marketplaces. While you won’t be able to find as many books at auctions, you may be able to find screaming deals.
8. Check out local bookstores. You may be able to find a good deal locally, especially once you factor in shipping charges. Even if you can’t quite match an online price locally, you’ll be able to see the book before you purchase and you’ll get the satisfaction of helping local merchants.
9. Consider used books. Used books are almost always cheaper than new ones, and if you can find a used version online in good condition it may be a good bet. You may also be able to get used books at your campus bookstore, especially if you shop early or pre-order. Compare prices to find the best deal. Also used books may have the previous students notes in them which is a plus because you won't have to make them.
10. Inquire about earlier editions. If the current edition's used price is still too much, use the book name to find an earlier edition: enter the book title in the search box and remove any references to what edition it is. Before buying, ask your professor or TA if the earlier edition is acceptable. It is often not acceptable because of changes to editions and page numbers, not to mention content, and you don’t want to have to pay for a book twice.
11. Scour your campus. Some colleges have student groups that sell used textbooks for older students or that otherwise facilitate buying and selling of books. Ask your friends, look at flyers around campus, and watch the student paper for deals.
12. Resell your books. If you don’t foresee that you’ll need a book after the semester ends, try to resell it as soon as possible. Find out what your campus bookstore and local booksellers will pay, and consider putting up flyers around campus and/or selling it online. If your book is in high demand, you may be able to sell a book online within a day, and at a much higher price than you’ll get at the bookstore.

Source: http://www.wikihow.com/Buy-Cheap-College-Textbooks