explainations about standard library and modules in Python.

[Hung ho]

Hi.
   I just finished reading an introductory Python book called "Python Programming for the absolute beginner" by Michael Dawson. I found it very interesting, and easy to follow. Python does really look similar to C/C++ and Java. In the book, the author imported other modules that were from the standard library of Python. I tried reading some of the modules in the standard library in Python's Lib folder. I'm just a beginner to Python, and didn't understand anything in any of the modules.
   My question is that, can anyone recommend me any book, or online materials that could explain what the functions some of the modules in the standard library can do that are packaged along with Python v. 2.3.4?. For example, I read some modules such as os.py, sys.py, and random.py The documents in those modules didn't help me to comprehend what the purpose of the modules, and how to use them in Python. What are their functions, and how do I use them.
   Thank You.