The basic on how to branch.

Nightly Branch Instructions

Review:
At this point you should have a local copy of the master, up to date.

Create the branch, push it, use it
$ git branch nightly
$ git push [git@github.com:...] nightly
$ git checkout nightly

(work your files)

$ git commit -a
$ git push [git@github.com:...] nightly

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Merge Instructions
$ git checkout master
$ git merge nightly
( fix any conflicts )
$ git commit -a
$ git push [git@github.com:...] master