I went back and forth about the license for a while. Basically, I chose one of the Creative Commons licenses because of all the work they are doing at evangelizing more reasonable copyright restrictions instead of the ridiculous controls the government seems fond of providing for content providers. I believe the license I have chosen fits very closely with the OpenContent.org one and can serve the Mozilla community well.
I'm quite surprised you chose the "Attribution-NonCommercial" variant, which would not make the book Free Software according to the Open Source Definition (so far as it could be applied).
Why did you choose that over the "Attribution-ShareAlike" one, which allows companies to publish your work with your name on the cover, and you get their improvements and edits? Everyone wins...
http://creativecommons.org/licenses/by-sa/1.0/
Gerv
