Don’t get any textbooks until the first class (unless your professor has specifically emailed you regarding the syllabus and assigned texts). The information on the website may be outdated, or the professor may provide some of the readings. Most professors will not expect you to have the books in the first class, and will spend the hour going through the syllabus. They may be okay with older editions of the textbook (that are often cheaper). See what you actually need, and only then start buying the books.
Unfortunately, some classes may require an online interactive textbook with an access key which has to be newly bought that usually cost a lot of money. But most other textbooks can be obtained for way cheaper!
Amazon usually has really good prices, especially if you are open to buying/renting used textbooks. The amazon lockers all around campus make the process of returning the rented textbooks a lot easier.
If you have time, google the title of the textbook, the edition, and the author followed by ‘free pdf/ download free’ etc (if you are feeling brave enough to torrent your textbooks, that’s also a viable option!)
Finally, the library! Go on the Claremont Libraries website and search for your books— some can be accessed online (and printed, you have a 2000 page quota each semester), and others can be borrowed (and you can renew them throughout the semester).
Discounts applicable to Pomona students around campus ASPC has a handy list of businesses close to Pomona that provide student discounts if presented with college I.D. To access this list, click here.
Dollarbird: tracks where you are spending your money