I used this guide to use git to autopublish my changes on my website when I push to my remote origin git repository:
http://www.lwp.ca/james/2010/03/using-git-to-man
You might start by getting post-update to echo some debugging output. Both standard output and standard error output are forwarded to git send-pack on the other end, so you can simply echo messages and you will see these on the client that you did git push. I assume you followed the guide to the word, made the post-update script executable, cloned the repo to the web folder etc.