Django

Django is a Python-based, Open-source web framework. And it's amazing. I'm currently going through the tutorial, which is fairly well written. There's nothing terribly amazing about the tutorial - it's not super entertaining, but it does present everything you need to get started working with Django, which is an amazing tool. To be fair I haven't worked with anything else like Zope or Twisted, so I don't know if they're any easier/more powerful.

However, Django seems to be real solid, and I'm liking it a lot. Plus did I mention it's free?