January 2015 update: these days I generally use the powerful SourceTree tool from Atlassian. While it’s great to be a purist, sometimes I just need to get the “job done”. The below still applies when I’m working exclusively in a shell (generally on a remote box).
These are some post-installation commands I use to get Git quickly into a working, friendly to use state - cherry-picked from http://git-scm.com/book/en/Customizing-Git-Git-Configuration:
# Required. Tell git who you are... appears in commit logs.
git config --global user.email "firstname.lastname@example.org"
git config --global user.name "Your Name"
# Optional! Some preferences to ease the eye and editing
git config --global core.editor nano
git config --global color.ui true