First create an empty repo on github named "agocontrol". After that run the following commands to pull from upstream:
mkdir agocontrol cd agocontrol git init git remote add upstream http://git.agocontrol.com/agocontrol/agocontrol.git git pull upstream master git remote add origin https://github.com/<your github username here>/agocontrol git push -u origin master
Create a branch on your fork and commit your contribution there. When you're done, pass the branch url to a member of the core team (you might want to join #agocontrol-devel on freenode IRC). We'll review the changes and pull accordingly.