This is the book that I recommend to colleagues who are learning Git. I still refer back to it on occasion when I get into tricky situations with Git. Looking forward to reading through this new edition.
I don't think you can go wrong with anything Git related by Scott Chacon.
There used to be screencasts by him that were really good, quick tutorials of running through common scenarios (branching, merging, rebasing, managing your stash). I haven't been able to find them in a while. Those were really great when I was learning how to do an interactive rebase.
I also recommend people to use the included "gitk" tool for visualized repository histories. It's absolutely criminal how most git tutorials never mention this tool.
There used to be screencasts by him that were really good, quick tutorials of running through common scenarios (branching, merging, rebasing, managing your stash). I haven't been able to find them in a while. Those were really great when I was learning how to do an interactive rebase.