Anti-Virus websites and resources

AVG Anti-Virus - Information and free antivirus protection for personal use
Network Associates Inc - Provides free specific virus removal tools and antivirus utilities
Panda Software Antivirus - Provides free online virus scanning and virus removal utilities
Sophos - no free tools but excellent information
Symantec - Provides free removal tools and manual removal tutorials and online security checks
Trend Micro - Provides free online virus checking

Spamming and blacklist resources

Open RBL - Basic but useful site which checks over 30 blacklists. Also excellent for finding information about domain names etc and resolving IPs to domain names.
Spamcop - Spam reporting service, excellent spam resources, info, FAQs etc. Check your mailserver against the blacklist here.
Distributed Server Boycott List - Contains list of IP address that show signs of being vunerable and that may be used as open relays. Check here to see if your IP address is blacklisted and request for its removal.
510 Software Group - Not purely spam busters, but check here to see if your IP address is listed.
The Spamhaus Project - Spam information, FAQ's etc and check your IP against the blacklist.
NJABL.ORG - Not Just Another Black List - Check your IP address here.
DNSSTUFF.COM - DNS and other networking tools
top

Windows shareware, freeware and general help sites

VMYTHS.com - Truth about computer virus myths and hoaxes
TechSupportAlert - Computer help plus links to free / shareware software
WhatIs.com - another glossary and help site
Tucows - Software downloads
Driverguide - Windows drivers
Freeality Internet Search Engines - Useful for finding all sorts of information
Major Geeks - Downloads and stuff
Event ID - Windows Errors
USB.org - USB News
Sourceforge - Open Source Software Development
Network Monitoring Tools

Windows stuff
Microsoft Technet - Online help for Microsoft products and technologies
Kinnettnet - Help on networking, office and windows plus more
Searchwin2000.com - Windows 2000 specific information resource
LabMice.net - Windows 2000\2003\XP Resource centre for IT Professionals
ActiveWin.com - The most activated Windows resource
Annoyances.org - Microsoft Windows resources

Cnet sites
Download.com - Free and shareware
Glossary - Computer terminology glossary
Help.com - Computer help forums
CNET Message boards - Technical message boards

Other general IT related sites

ITWorld.com
The Register
Wired
Slashdot

PC Hardware, performance, customising, help and tuning

SysOpt.com - System optimization information
Adrian's Rojak Pot - PC optimization and customizing
TechSpot - PC hardware and software stuff
Toms Hardware Guide - All things PC
Motherboard Review - Home of the motherboard review database
System Cooling - Cooling products and advice
Mashie - The Art Of Computers
RipNet - All Things Computing
OverClock Intelligence Agency
AMD3d.com
Club Overclocker - The original overclockers club!

CD Covers
Skinbase
Desktop Wallpapers
Cover Target

ADSL and Broadband

ADSLguide - The UKs largest Independent ADSL review site
BT Broadband - with availability checker for your area
Broadbandstuff
World Of Adsl

Linux

Linux Refresher Course - Linux tutorials and help
Linux Online - Linux homepage at Linux Online
Linux Help - For all your Linux needs
LinuxQuestions.org - Where Linux Newbies come for help

Technologies

XML - XML Cover Pages
XML - XML.com
XML - XML at O'Reilly