How can I become a hacker?

`You can't. But you can read about us!`

Actually many things can be hacked, but since my specialty is computers, internet, and crypto, I'll give you my reading list:

The monthly web newsletter Crypto-Gram
The continually-updated pseudo-news site SlashDot (read the headlines, but don't waste your time arguing)
The Register, a news site with attitude.
Vulnerability information (and more) at Security Focus
Other sites: EFF 2600 attrition Risks HackerNews Counterpane Labs
Other other sites: Ross Anderson Cap-Lore (Norm Hardy) Carl Ellison
This book [yeah, dead trees]: Secrets and Lies : Digital Security in a Networked World
Google Directory: Hacking Hackers
The weird documents at Cryptome (you won't understand most of this)
Eric Steven Raymond's How To Become A Hacker
Fyodor's Good Reading List
Older online texts: Hakim Bey's TAZ (1985-1991); Tim May's Cyphernomicon (1994); Bruce Sterling's book The Hacker Crackdown (1992) and various writings. HH's The History of the Net
And why not browse The Yak
(here's an older page of mine with similar links)
Who are strick's net.gods?

Other worthy books:

Hackers - Heroes of the Computer Revolution Steven Levy. Levy gives an eminently readable (and non-technical) overview of how hacking culture developed, from the days of TECO and PDP-11's at MIT, up to the phreaker / BBS culture of the late 80's and early 1990s. This book inspired me to start writing code, wire networks, and play around inside SprintLink as a freshman in HS :-).
Where Wizards Stay Up Late: The Origins of the Internet I picked this slim paperback up last year, expecting it to be a diluted, shallow account of Internet history, written for your typical AOLer. I was pleasantly surprised to discover that Hafner & Lyon paid good attention to detail, and gave a good account of the people, politics and technical issues that surrounded the birth of ARPAnet, and its eventual merge into the larger Internet. Very readable, and includes some historic images of early hardware and the people who made it all happen.
Eric S. Raymond has a draft of a document entitled The Art of UNIX Programming, which is as much a philosophical treatise on the mind-set needed to write good code in the UNIX environment, as it is a technical reference. Very good reading... ESR speaks wise words. Every young programmer should read it.