A few of my favorite security links:
www.insecure.org has all kinds of utilities for testing your network security.
www.securityfocus.com has the latest and greatest news on the security homefront. I’d like to try and list their RSS feed here someday.
www.grc.com is from the guru who brought us SpinRite oh-so-many years ago. You computer old-timers know about this product. Steve Gibson’s site has some pretty cool utilities and you can always try his Shields-Up test on your PC to see if you have any leaks.
www.dnsstuff.com allows you to look up all kinds of DNS info.