no it is free for noncommercial use. The github website guides you through the process: you can create a new project in your browser, then clone the empty project to your pc. Then you copy the files into this folder, add them, commit them and push them, then they are online.
You should take care to get rid of passwordfiles or hardcoded passwords and such from your code befor you commit the files; once it is in git it cannot be removed.
There is a free book online that describes how git works: http://git-scm.com/book and youtube has several tutorials also.