Tips on how to read code?

Jeremy's asking:

So how do you teach people this “art” of digging deep very quickly into unfamilar code that you had no hand in writing? I myself, I come from a very traditional process of learning how to code.. by sitting down and writing it. I am struggling with how to tailor a delivery to focus on reading vs. writing source code. To me the only way you can be truely efficient in this process is by having written code yourself.