I like books. They are doors which can often lead in profitable directions in every conceivable sense. Therefore, I have some and try to get more. But there are a couple of problems this sort of behavior can lead to, including the fact that books can be expensive and therefore costly. Of course I repeated myself; it is a fact doubly worthy of consideration, especially since it leads up to my point, which is that you need a inexpensive method of obtaining books.

Buying used books is usually the best way to get a good deal and the Internet is full of good places to search for these sorts of things; here are a few places I like to go when looking for a book, used or otherwise:

Amazon Used book section
Froogle
ABE Books
eBay

Christian Book Distribution
Solid Ground Books
Reformation Heritage Books
Cumberland Valley Bible Book Service