How can a total, complete beginner read source code?
Donald Knuth suggests:
"It [is] basically the way you solve some kind of unknown puzzle -- make tables and charts and get a little more information here and make a hypothesis."
(From "Coders at Work", Chapter 15)
In my opinion, the easiest way to understand a program is to study the data structures first.  Write them down, memorize them.  Only then, think about how they move through program-time.
As an aside, it is sort of a shame how few books there are on code reading.  "Coders at Work" is probably the best so far.  Ironically, "Reading Code" is one of the worst so far.
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.