start with a python micro-framework. I highly recommend flask (http://flask.pocoo.org). Go through their exercise of creating a simple blog. Then start looking at their extensions which are also awesome.
Also you don;'t really need to learn Jinja etc. separately. Flask does enough to get you started. For example, I can easily build routing using app.route() decorator in flask which in the back is using Werkjeug. I honestly don't know much about werkjeug itself (yet) but that did not stop me from building a fully functional web app. Of course, if you really want to get in the details, you learn the individual libraries that gives you flexibility to build a real work production app. YMMV
Mostly I think it's nice to know "this goes here, this goes there" and have nice obvious examples of where to go next.
Just looking at the front page and tutorial for flask, I wouldn't be thrilled about it. Writing SQL, for instance.