While researching some CrossFit moves I found this:
The Official CrossFit Training Guide

This is the reading they give to candidates prior to their Level 1 Certification class.  It is really interesting and provides some awesome information about what CrossFit is all about.  It also goes through, in detail, the 9 fundamental movements of fitness and common mistakes.  It is 115 pages so not light reading.

I have gotten through just the beginning, the "what is CrossFit" kind of stuff, and it has really solidified my understanding of what it is I am doing and why.  Great resource.

Don't know why or if it is supposed to be available for free like that but enjoy it while it's there