Why don't you look for manuals about the type of system/OS you want to "hack". I would recommend learning about Unix, Linux, BSD, Apache, etc. That's a good place to start.
Look into some programming languages like C++, perl, cgi, SQL, Java, maybe look into some scripting like Javascript. Assembler once you feel you've mastered a language or two. The best hacking tools are homemade, "custom fitted" you could say.
Of course... this is all just suggestion. It depends on what you want to do, in general terms.
Oh yeah... one last thing. Allocate some brainpower to BlackKnight's sig... see if you qualify. Good luck.