Good introduction material (Chinese) for git: link
For Git server, you could use GitHub or build one git on your own machine/server.
This is good guideline (Chinese) for how to build git server on your linux machine. Actually it is very simple: install git on your server and create user git. Then you could use ssh to visit home directory of git. I spent 1 hours to build up server. The main problem is I put "/" instead of "/home/git" in /etc/passwd. $HOME is very important since ssh need it to find ~/.ssh/authorized_keys.