This document is intended to serve as a knowledge base about Git and the supporting tools around. It's intended to be rewritten and added to at your will. If you know awesome links, please add them here so we can all share some knowledge :)
A guide to git from Standford: http://www-cs-students.stanford.edu/~blynn/gitmagic/ch02.html#_add_delete_rename
A seemingly pragmatic guide to getting started with git: http://gitimmersion.com/
Why duplicate the internet, here's a blog post listing good tutorials: http://sixrevisions.com/resources/git-tutorials-beginners/
If you're familiar with versioning as a concept, here's an interactive guide to git: http://try.github.io/
If you want to learn more about branching: http://pcottle.github.io/learnGitBranching/
If you want to see git being used in action (I assume you're already using git but want to up your skills a notch) then I would definitely recommend checking out Gary Bernhardt's screencasts (paid) over at https://destroyallsoftware.com/ . Plus you then also get to learn about the wonders of the unix command line :)