How can a total, complete beginner read source code?
I would recommend you understand the basics. What are methods, classes, variables and so on. It would be important to understand the constructs you are seeing. If you don't understand those then it's just going to be a bunch of characters.
I am a complete, total beginner in programming, although I do have knowledge of CSS and HTML.
I would like to learn Python. I downloaded lots of source code but the amount of files and the complexity really confuses me. I don't know where to begin. Is there a particular order I should look for?
Thanks.
EDIT: Sorry guys, I forgot to mention that I already have both the online tutorial and a couple of books handy. I basically I don't quite understand how to "dismantle" and understand complex source code, in order to grasp programming techniques and concepts. 
EDIT2: Thanks for the extremely quick comments, guys. I really appreciate it. This website is awesome.