pre- steps for python web developing?

Nowadays I am trying to proceed a self-learn python programming in order to get familiar with python web developing. I have chosen my road map and I want to be a Python web developer. but my question is what are the prerequisites? 1. will some information about network be needed in my way? 2. what are the steps before starting web developing? 3. should I choose Django Framework or Flask? 4. Can you introduce the most comprehensive books in this subject?