Very interesting references for GitHub:
– http://git-scm.com/docs
– https://help.github.com/categories/54/articles
– https://guides.github.com/activities/hello-world/
– http://git-scm.com/book/en/Getting-Started-About-Version-Control
– http://semver.org/
– https://guides.github.com/features/mastering-markdown/