Take this advice if money is important to you:
The trick is to never, ever buy a new book and never buy from your bookstore. I'm dead serious.
Find out what books you will be using (make sure it's the right edition) and buy from Half.com or Amazon used book sales. When the semester is over, sell them right back on the same site for a similar price (sometimes you can even mark the price up a bit if you got a good deal and other people are selling the same book high).
I started doing this second year and wish someone would have told me about this coming into first year because I probably spent less than 200 dollars on books this year counting what I make back from re-selling.
If you just have to have new books then this won't work. However, if money is an object for you then you can certainly get by with used/marked up books.