Do you spend all summer making that hard earned money, only to spend it all on textbooks when you get back on campus? Some students end up spending over $400 on textbooks a semester when you buy them from the school store. Prices get higher and higher, textbooks get updated every year, and professors always want the brand new edition of the textbook.
First off, rent your textbooks. I highly doubt that you will crack open a textbook after college. In this day and age, everything is being put online. If you really think that you would use portions of the textbooks after college, then I suggest bringing the book to the library, and digitally scanning pages from the textbook. Also, the library should have a copy machine if you want a paper copy.
Next, don't wait until the last minute. The longer you wait, the higher the textbook prices will be. If you wait until the first day of classes, you will be just like every other college student and you will end up paying close to double the price that you could have paid.
Lastly, ask around. Ask whether or not the professor will actually make you use the textbook. Ratemyprofessor.com is a great resource showing whether or not other students in the past have used the textbook during class and if it is even worth purchasing in the first place.
Here are some options for those of you who haven't bought their textbooks yet and who would rather be spending their hard earned paychecks on other college things.
Amazon Student is a wonderful resource. Not only can you get two day shipping, but sometimes textbooks used end up being really cheap. If you only need a book for class too, sometimes you can find them on their website for less than $5. They also will allow you to rent textbooks, and I have found that they are overall the cheapest resource to order your textbooks from.
Chegg is also another gift to a college student. Chegg will let you rent textbooks for around $30 per semester. They do a great job of realizing that students don't want to break the bank when they purchase their required textbooks. For the super expensive Biology or Chemistry books, Chegg is the place to go. Chegg also does free shipping with returns, so when your bank account is excruciatingly low at the end of the semester, you won't have to pay any shipping fee.
Textbook Rentals is a great tool when you first get your list of required materials. They will compare the lowest prices on all of the sites and then offer you the best deal. Also, currently they are giving away free t-shirts even if you just like their page on Facebook.