github help has an excellent series of how-to guides.
learn.github has an excellent series of tutorials
The pro git book is a good in-depth book on git.
A git cheat sheet is a page giving summaries of common commands.
The git user manual
The git tutorial
The git community book
git ready - a nice series of tutorials
git casts - video snippets giving git how-tos.
git magic - extended introduction with intermediate detail
The git parable is an easy read explaining the concepts behind git.
Our own git foundation expands on the git parable.
Fernando Perez’ git page - Fernando’s git page - many links and tips
A good but technical page on git concepts
git svn crash course: git for those of us used to subversion
There are many ways of working with git; here are some posts on the rules of thumb that other projects have come up with:
Linus Torvalds on git management
Linus Torvalds on linux git workflow . Summary; use the git tools to make the history of your edits as clean as possible; merge from upstream edits as little as possible in branches where you are doing active development.
You can get these on your own machine with (e.g) git help push or (same thing) git push --help, but, for convenience, here are the online manual pages for some common commands:
git help push
git push --help
git add
git branch
git checkout
git clone
git commit
git config
git diff
git log
git pull
git push
git remote
git status