FOSS gamedev and creative worlds

I wasn't sure where to put this- sorry if it is in the wrong place.
Okay,I am new to github. I have created a repo for a mod, but how do I actually add the mod to it? Thanks in advance for any help.

http://git-scm.com/book/en/Git-Basics-Getting-a-Git-Repository
http://git-scm.com/book/en/Git-Basics-Recording-Changes-to-the-Repository
Read these pages completely