Hacking is an art. It is a skill which isn't limited to a computer or network, it is much more than that. It is a thinking. So, a good hacker isn't just good with computers but also has that thinking.
The above is what I believe in. You may or may not believe I'm that.
So, the real question is from where should and individual start. I will try to keep it simple and brief. Here is my opinion step by step :-