Codecademy Labs. Become a Programmer, Motherfucker. If you don't know how to code, then you can learn even if you think you can't.
Thousands of people have learned programming from these fine books: Learn Python The Hard Way Learn Ruby The Hard Way Learn Code The Hard Way I'm also working on a whole series of programming education books at learncodethehardway.org. Introduction to Algorithms - Download free content from MIT. The Basics of C Programming& - StumbleUpon. The previous discussion becomes a little clearer if you understand how memory addresses work in a computer's hardware.
If you have not read it already, now would be a good time to read How Bits and Bytes Work to fully understand bits, bytes and words. All computers have memory, also known as RAM (random access memory).