Tools: Books

AddALL Book Search and Price Comparison (free)
A search engine specifically to assist with tracking down the best deal on books and other media. Searches more than 40 sites. Allows searches for ebooks, used books, magazines, music, movies, and in print books.

Bookfinder (free)
A search engine to find used books, rare books, textbooks, new and out-of-print books.

Calibre (free)
Ebook management.

EPubsoft Toolbox (one time license)
Helps you remove DRM from ebooks and convert your ebooks to other formats quickly.

Project Gutenberg (free)

Public Books Database (free)
Database of free books from academic presses.

Standard eBooks (free)
Produces new editions of public domain ebooks that are lovingly formatted, open source, and free.