There are perhaps hundreds and thousands (and more) of good Hacking and Security sites all over the world. The below list may not be complete, but one can get interesting articles and references from these sites.
1.
www.hackersplayground.org Go and play there.
Subscribe in this group and you will get the latest security related incidents, Security related books, white papers,etc.
Some useful codings (in Unix and Linux Security), research papers ,etc..
This is a site which couldn't be easily found in search. You can find a lot of information related to cryptography, E-mail security, etc.
5.
www.insecure.orgOpen Source penetration testing tools like tools like nmap, various exploit code , etc.