FirewallSupport.com 
Online support service specifically focused on firewall security. Information and resources to troubleshoot firewall problems.
http://www.firewallsupport.com/DShield 
Distributed Intrusion Detection System collects firewall log excerpts from volunteers. The logs are aggregated and analyzed. Several reports are generated showing trends in attack sources and methods used.
http://www.dshield.org/
COAST Internet Firewalls Hotlist 
A list of firewall vendors, white papers, resources, and FAQs.
http://www.cerias.purdue.edu/about/history/coast_resources/firewalls/
The Freefire Project 
Dedicated to users, administrators and developers of IT security solutions (especially firewalls) based on free software. It features a large tool overview, some articles on IT security and links to other resources.
http://sites.inka.de/lina/freefire-l/index.en.html