I own the book (hacking exposed 3rd edition). It's a good book. There's a lot of books out there that could help. Go to your local bookstore / libarary and look at a few books in the computer section. Like a lot of people recommend, tcp/ip and networking books of that sort are good, but you should also read up on how different operating system works. Programming wouldn't be a bad idea ither. A GOOD website for reference would be
Spdstr. It does keep track, I know every person that's visited my website. What they looked at / downloaded and what time too. I know everytime someone has logged into the box and failed attemps too.
Although what about Linux viruses? pshhhhh, no one hates Linux enough to write one.
Reiken, there are viruses on linux. Enough for ClamAV to be released. http://clamav.net/
The problem is a lot of these sites / communities are run by lamers with their big ego, sit in irc all day and flame eachother. Their sites lack update, exploits get patched.
Knowledge is power. The problem with a lot of these sites. It's just the same content over and over again, mostly.
If you have someone else teach you, you're limited by their knowledge. If you teach yourself, you're limited by your capabilities.
Hacking is a skill you develop yourself. Sure you can have people share knowledge, but you can't really teach people how to hack, it's something you figure out on your own.
That's just what I think.