Network Security, Filters and Firewalls
General introduction to network security issues and solutions in the Internet
http://www.acm.org/crossroads/xrds2-1/security.html

Common Vulnerabilities and Exposures
A searchable database of internet security problems.
http://www.cve.mitre.org/

Dingbat's Warehouse
Information about viruses, intrusion detection software, personal firewalls, and privacy. Hosts a streaming webcast called The Byte Show on security-related topics; CD-ROMs of interviews and software available.
http://www.thebyteshow.com/

SuraSoft
Offers news, tutorials, articles, and forum.
http://www.surasoft.com/

About.com Internet/Network Security
Featuring articles and web links on Internet and network security for the Unix and Windows platforms.
http://netsecurity.about.com/index.htm

Dutch Security Information Network
Security news and links in English and Dutch.
http://www.dsinet.org/

My online security
Security portal, providing internet security related news, resources, tools and services.
http://www.myonlinesecurity.com

Intrusion Detection FAQ
Frequently asked questions about intrusion detection, from the SANS Institute.
http://www.sans.org/resources/idfaq/

Stay Safe Online
Tools and resources to empower home users, small businesses, schools and universities to stay safe online.
http://www.staysafeonline.info/

ITsafe
UK government security service to help protect computers, mobile phones and other devices from malicious attack. Offers advice, bulletins, glossary, library and links plus an alerting service.
http://www.itsafe.gov.uk/

Firstmonday - Covert Channels in the TCP/IP Protocol Suite
Article on how to secretly transmit information using TCP headers.
http://www.firstmonday.org/issues/issue2_5/rowland/

Google Online Security Blog
News and insights from Google on security and safety on the Internet.
http://googleonlinesecurity.blogspot.com/

Google Online Security Blog
News and insights from on security and safety on the Internet.
http://feeds.feedburner.com/GoogleOnlineSecurityBlog?format=xml