Great tutorial, a good level of detail too.

The only other thing i'd mention for Flask newbies would be the excellent debugger facility in Werkzeug (effectively a part of Flask).

I lied, one more reference - the guy that wrote flask (bit of a genius, also has a bunch of other excellent libraries) has shared slides from some talks he's given, they're really worth a read too: http://lucumr.pocoo.org/talks/

Bucket list 2013, attend a talk by Armin Ronacher.