Pro Git Book writes:

I put the content of the book online under a Creative Commons noncommercial 3.0 license. The book is titled ‘Pro Git’ and you can read it or reference it online at The actual printed version will be shipping in another few weeks, but as Apress was kind enough to allow me to publish it under the CC license, you can take a look now. I hope it’s helpful to you in learning or teaching Git.