git ready contains many tips for using Git from beginner to advanced. See Also the git Wiki for all kinds of documentation and tips on how to use Git.
Here are a few things that are good to learn and not obvious.
Reorder a series of commits:
git rebase -i <base-rev>
Find what commit broke your unit tests, in this case make check ; you can use any other command that could check for some specific build failure or error and exit with a non-zero status on failure:
git bisect start HEAD <known good revision>; git bisect run make check
Show useful information about the remote and its branches:
git remote show <remote>
And forking in Git is easiest:
git checkout -b branch-name master
If you want to share the branch with others while working on it or redirect it to the server for backup:
git checkout branch-name
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