Thanks for the replies guys!

The tutorial i linked in the OP was coincidentally that one from Lenas, and I like that page (tuts4you).

Quick question though, arent those tutorials little old? I am doing it and im learning tons with it but can i safely assume that i will encounter most of it in "real life" applications.

I will start learning assembly + checking compiled code as suggested.

--Edit
Let me fit in another question here:
I have noticed that there might be different "flavors" of ASM language. Is that correct? if so what would be the way to go?