Here are some online resources you might find useful.

Google

For standard Python modules, typing something like "Python random" into Google usually gets you the info you need.

Wiki

The Python Programming Wikibook is not too bad. This is a work in progress, often minimal. It is useful if you want a quick overview of something (e.g., what you can do with strings, lists, and dictionaries.)

The full Wikibook is available here: Python Programming

Official Python Docs

If all else fails, you can consult the official Python documentation. This is not written for beginners, but it can be quite useful. This should become more useful as the term progresses.

Library Reference

Modules, etc.: Python Library Reference

Language Reference

Only for extreme situations: Python Reference Manual

Python Style Guide

Guido van Rossum, the creator of Python, has written a Python Style Guide. This contains layout and naming conventions for the Python language. These conventions will help you write code that is easily readable by others.