Hi!
I've learned what I know of git online. Now other developers at work need to learn it too, and we want to try to purchases books for that.
I found two options:
In the descriptions I read, O'reilly's seems to give more examples, typical work-flows. But the Pragmatic book is referenced more often.
We need a book for beginners, but that also covers more advanced topics, like the integrators role, submodules, ...
Has anyone any idea about which one we should get?
The Pragmatic books have always been easier to read. The format is a little less technical and they usually show the best way to use the version control. O'Reilly is usually decent, but not quite as good as the Prags.
You might want to have a look at Pro Git, from Apress, and see if that fits your needs.
This stack overflow question has some comments about the pragprog book.
I heartily recommend Pragmatic Version Control with Git it has enough information for a beginner to get started, but also touches upon common usage in the course of an average developer's day. Plus I found the writing to be clear and concise, so you find it easy to read and digest unlike the more typical dry "instruction manual" type books.
There are two stages to learning Git. The first is where you learn how to do basic CVS/SVN-like version control with Git. This you can get from a lot of the online tutorials and from the two published books you reference.
But if you stop there, you're missing so much. The second stage of learning Git is where you really get Git and see it as a toolkit that operates on a simple and well defined data model. The two published books don't do this stage much justice.
Be sure to checkout the excellent PeepCode PDF book (US$9) Git Internals. A free article along the same lines is Git From The Bottom Up. Both of these references will help you better grok the essence of Git ("content addressable data store", DAG, data model, etc.). That, in turn, will help open your eyes to the marvels of things like cherry-picking, rebasing, merging, etc. They'll strip away some of Git's magic and help you understand all of the cool things you can do with Git (many of which aren't in a simple, one-line command).
Update: The Pro Git book is now available in print and free online. That's an excellent book along the lines of the Git Internals book but complete with basic usage, git-svn, submodules, example workflows, etc. The source for the book is, of course, available on GitHub. Highly recommended.
I started with the PragBook, first ecopy then hardcopy. But I was missing something. Then I got the Pro Git and it clicked, either by new info or repetition in my head. For something that can and should be used for the rest of your career, getting both those books and maybe the O'Reily are good options. I am ordering my O'Reily copy as well, and that will provide 3 viewpoints into this system.