Here is "Guides: Using the EGit Eclipse Plugin with GitHub": https://github.com/guides/using-the-egit-eclipse-plugin-with-github

However, Egit could not connect by ssh on Windows when I used cygwin for ssh+git. Egit try to find .ssh on HOME directory on Windows(C:\Users\makoto_kw), but it is on HOME directory on cygwin(/cygwin/home/makoto_kw).

I could relate to .git with Egit after importing a project

  1. git clone on cygwin
    • git clone git@github.com:makotokw/php-twient.git
  2. Create new project on Eclipse
    • Chose directory cloned above
  3. Context menu of the project > Team > Share Project... > Git
    • Egit find .git automatically and select "Finish" button

That's all!