This page will be divided into two sections: Christian and secular (secular can be Christian or not).

Christian

Christian Classics Ethereal Library
Classic Christian books in electronic format.

Calvin's Works at CCEL
A quick link to the books by Calvin available at the CCEL.

Foundation for Biblical Studies
A great resource for the study of a variety of topics from a Christian standpoint.

Theology at the FBS
Books, literature, and sermons by great Christian men.

Cumberland Valley Bible Book Service
CVBBS makes Christian books and Bibles available at discount prices. They specialize in supplying Reformed and Puritan books at prices that make them affordable to everyone.

Ages Software
Classic Christian writings on cd... your own affordable digital library.

Secular

The Stephen R. Lawhead Website
One of my personal favorite modern-day authors, Stephen Lawhead is the author of Celtic, Arthurian, fantasy, and science fiction novels, as well as historical novels concerning the Crusades and the Knights Templar.

BookCloseouts.com
Really really cheap books.