Now, hacking is different from cracking.
Hacking, also called Ethical Hacking, is done to test the security of the computer systems by breaking into it, like the real attacks, but no damage is made, this is to evaluate the security and then ethical hackers report it back to the owners.
But in Cracking, crackers break into the system to deliberately make damages to it.
Actually, Rooman Technologies has a course called EC Certified Ethical Hacking , in which some of the tips/tricks/methods used by the true blue hackers are taught, like DDos, System Hacking, Hackin WebServers, Session Hacking and more.
Reading books and trying/experimenting them on a system is the only way to become proficient in Hacking.........