Not much...
1. Install github client (for windows)
2. after installing go to AllPrograms >GitHub > git shell
3. git console should appear.
Now, after you have git installed, lets start with some basic operations:
To get the code from remote repository to local:
1. browse to some directory where you want your local repository to be
2. type: git clone https://github.com/someuser/YOUR_REPO_NAME.git
If all the things is correct - the local repository with all its contents should create.
Congratulation! you just became a git user