Neat! Great to have an ecosystem of content starting to grow. The Creative Commons license chooser is a good way to go: http://creativecommons.org/choose/. And their "before licensing" page is pretty good too: http://wiki.creativecommons.org/Before_Licensing.
I was disappointed when I clicked through to OP's submission. As with the Flynn post yesterday, I'm glad to see at least he's not the only game in town. Unfortunately I am not able to reach github right now. The isup.me site says I'm alone in that. Does anyone else have this problem now?
It is on github, and pull requests are welcome. It is currently written for Docker 0.5. I will keep it up to date, and when we hit 1.0 I'll look at getting some hard copies made, if there is a demand.
I still need to pick a license, not sure what is best for a book, open to suggestions.