Git Documentation
Git glossary ( HTML version, source via gitweb)
Git manual page - Online version bundled with Git. (The information displayed when using the command man git or git help)
Git User's Manual - Online version bundled with Git
A tutorial introduction to git and A tutorial introduction to git: part two - Online version bundled with Git
Everyday Git, with 20 commands or so - Online version bundled with Git
Git for CVS users - Online version bundled with Git
Git SVN crash course
Many Howto documents come with git as well
Documentation/technical for all the technical information relating to Git