After reading a blog post about git in a minute, I figured I should jot down the git commands that I use. This is definitely a good way of distilling the core information.
https://www.garyrobinson.net/2014/10/git-in-two-minutes-for-a-solo-developer.html
This is what I would consider the most useful git commands :)
Start a git repo:
git init
Add files
git add --all
Commit
git commit -m "message"
Add and commit
git commit -a -m "message"
List previous commits and their hashes
git log --pretty=oneline
Show a previous version
git show {hash}:/path/to/file
Roll back to a previous version
git checkout {hash} -- {filename}
Undo a commit
git reset HEAD^
Undo a specific commit
git reset {hash}