First-Time Git Setup

this article reference following url:
http://git-scm.com/book/en/Getting-Started-First-Time-Git-Setup

First-Time Git Setup

Now that you have Git on your system, you’ll want to do a few things to customize your Git environment. You should have to do these things only once; they’ll stick around between upgrades. You can also change them at any time by running through the commands again.
Git comes with a tool called git config that lets you get and set configuration variables that control all aspects of how Git looks and operates. These variables can be stored in three different places:

• /etc/gitconfig file: Contains values for every user on the system and all their repositories. If you pass the option--system to git config, it reads and writes from this file specifically.
• ~/.gitconfig file: Specific to your user. You can make Git read and write to this file specifically by passing the --global option.
• config file in the git directory (that is, .git/config) of whatever repository you’re currently using: Specific to that single repository. Each level overrides values in the previous level, so values in .git/config trump those in /etc/gitconfig.

On Windows systems, Git looks for the .gitconfig file in the $HOME directory (C:\Documents and Settings\$USER for most people). It also still looks for /etc/gitconfig, although it’s relative to the MSys root, which is wherever you decide to install Git on your Windows system when you run the installer.

Your Identity

The first thing you should do when you install Git is to set your user name and e-mail address. This is important because every Git commit uses this information, and it’s immutably baked into the commits you pass around:

$ git config --global user.name "John Doe"
$ git config --global user.email johndoe@example.com

Again, you need to do this only once if you pass the --global option, because then Git will always use that information for anything you do on that system. If you want to override this with a different name or e-mail address for specific projects, you can run the command without the --global option when you’re in that project