The full post of how to setup gitosis and other git repos is found at scie.nti.st.
Here are some commands I have found helpful and that I do each time I set up a git repo.
First I usually check the gitosis-admin to make sure the conf file is set up to handle the users and the projects I'm putting into gitosis. They public key obviously has to be copied over as well. Git push to make changes to the gitosis-admin.
Then to putting a repo up to the server.
mkdir free_monkey cd free_monkey git init git remote add origin email@example.com:free_monkey.git
git push origin master:refs/heads/master
In order to do this last step so that I don't have to type more than
git push, I add the following to my .git/config:
[branch "master"] remote = origin merge = refs/heads/master