http://michaelcrump.net/setting-up-github-to-work-with-visual-studio-2013-step-by-step/
1. Create github account from github.com.
2. Create new repository in githut and copy the address.
3. In Visual Studio 2013, File->Add to Source Control.
4. Choose 'Git' and input your repository address.
If you would like to use and existing repository, you should clone the repository to local via Team Explorer->Connect to Team Project.