Security

(ISC)2
The premiere security certification organization in the world.
ISACA
Information Systems Audit and Control Association.
Sans
The trusted source for computer security training.
Security Focus
General reference security site.

Security Tools

Wireshark
Open Source Packet Sniffer
Backtrack
Boot Linux with Security Tools pre installed
Nessus
Open Source Security Scanner
Nmap
Fyodor's premiere open source port scanning tool
Metasploit
Free exploitation framework
Gooscan
Automated Google scanning tool
BiDiBlah
Automated attack process tool
THC-Hydra
Free password guessing tool

Audit Resources

Audit Net
I.T. Audit Resources

Training Resources

Big Nerd Ranch
The Canyon Ranch of Open Source /Apple/ Technology Training