Here is another piece of common git commands I keep forgetting. I think the reason I keep running into these issues is that I keep switching between Git and Mercurial for certain projects.
Add your username and email to the global git ==version 1.9.2== config:
>>> git config --global user.name "Your username"
>>> git config --global email "Your email address"
Specify a default editor after you run git commit:
>>> git config --global core-editor your-editor-name>