Free for All
   Full text of Peter Wayner's book, subtitled "How Linux and the Free Software Movement Undercut the High-Tech Titans". [PDF]
   http://www.wayner.org/books/ffa/

Open Sources: Voices from the Open Source Revolution
   The full text of this O'Reilly book has been made freely available online.
   http://www.oreilly.com/catalog/opensources/book/toc.html

Perspectives on Free and Open Source Software
   Book edited by Joseph Feller, Brian Fitzgerald, Scott A. Hissam and Karim R. Lakhani. Site includes full text as PDF downloads of each chapter.
   http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=11216

Producing Open Source Software - How to Run a Successful Free Software Project
   Book by Karl Fogel. Full text freely available as HTML, PDF, and XML.
   http://producingoss.com/

The Linux Cookbook
   All-encompassing book on using open source software, which itself is open source and available online.
   http://dsl.org/cookbook/