Scene 1: You've run npm start, focus your browser to localhost, and you see nothing. Inspecting your code, you see one or two errors and fix them. Reload, still nada.
If your running OS X, I'm going to offer you something that works for me to help get that new dev computer on a path to less frustration.
$ sudo easy_install pip $ sudo pip install https://closure-linter.googlecode.com/svn/trunk/
Tada! RTFM! Tada!