[Merkuri]

Basics of website hacking - You should learn PHP, the most of popular vulnerabilities are in the web site hacking section here.
For stealing information you will need to learn controlling botnets, RATs and other malicious tools and SE

[Ultimatum]

Join a group that is willing to teach you, it's much easier than a dead text which can't elaborate. Everybody else seems to have covered most.

Please remember, if you have a botnet, RAT or something like this, then it's not hacking. Any noob can do it.