http://packetstormsecurity.org - For all of the latest tools, advisories, and exploits
http://www.sys-security.com - Most of the info Iíve learned about ICMP came from articles from this site! All you wanted to know/learn about ICMP packets can be found here.
http://www.gfi.com/lannetscan/ - Languard Network Scanner 1.1, what got me interested again in security.
http://www.snort.org - IDS
http://slashdot.org/ - News for nerds site as they put it
http://standards.ieee.org/regauth/oui/oui.txt - MAC Address Vendor Code List - what Satori uses when I can keep it up to date
http://www.packetfence.org/ - NAC solution that uses DHCP fingerprinting and guys I've worked a bit with
http://www.fingerbank.org - DHCP fingerprinting site that Dave put up and we are working on filling up with all our DHCP fingerprints!
http://www.lawncareboise.com/ - Local Lawn Care company that I told I'd put a link on my website for. If you happen to be in the Boise Idaho area and need lawn care, give them a call!
http://www.counterhack.net/Counter_Hack/Welcome.html - Counterhack Reloaded. Covers a lot a great material
http://www.amazon.com/Gray-Hacking-Second-Shon-Harris/dp/0071495681 - Gray Hat Hacking: The Ethical Hacker's Handbook. 2nd Edition. One of the authors is someone I've known since childhood. Some of it made a lot more sense after my latest SANS course!
http://lcamtuf.coredump.cx/silence.shtml - Silence on the Wire: A field guide to Passive Reconnaissance and Indirect Attacks. Parts of it I really liked, parts were outside of my scope of care.
http://www.amazon.com/DHCP-Handbook-Kaleidoscope-Ralph-Droms/dp/0672323273 - The DHCP Handbook. 2nd Edition by Ralph Droms. Got some good info out of this for my DHCP Paper.
http://www.amazon.com/Stealing-Network-How-Own-Box/dp/1931836876/ref=sr_1_1?ie=UTF8&s=books&qid=1212891157&sr=1-1 - Stealing the Network: ... Multiple books in the series. Expensive for a "novel", but a good read IMHO. 4 Books in all right now I believe.
http://www.amazon.com/Anti-Hacker-Tool-Third-Mike-Shema/dp/0072262877/ref=pd_bbs_1?ie=UTF8&s=books&qid=1212891049&sr=1-1 - Anti-Hacker Toolkit. 3rd Edition. First Edition was great compared to a lot of the other books like this, not sure if they've kept that up though.