SpeedGuide.net - The Broadband place. Everything about cable modems, DSL & Satellite with large section on free speed optimizations, general Windows tweaks, tips and fixes for boosting system performance.
A public service brought by Internet industry corporations and public interest organizations to help insure that families have safe, constructive, educational and entertaining online experiences.
SANS Internet Storm Center - A global cooperative cyber threat / internet security monitor and alert system. Featuring daily handler diaries with summarizing and analyzing new threats to networks and internet security events.
SecurityFocus is designed to facilitate discussion on computer security related topics, create computer security awareness, and to provide the Internet's largest and most comprehensive database of computer security knowledge and resour...
Excellent source of information, tools and news for all things related to ISP providers, line quality/speed and other tests, broadband news/issues etc.
Not only does this site cover just about all phases of the internet from ISP's to troubleshooting your connections. There are many, many other forums. Everything from Graphics to Home Improvement to Computer Repair can be found there.
If you want information on a wide variety of subjects this is a must see site.
Solid ISP news website: Dslreports.com is a site that keeps you informed and up to date on Internet Service Provider News. Would recommend it to anyone in the business or at least has an interest in it.