Wireless
Corrupted Firmware Fix* - Sad to say, I've needed this advice. However, it is good as gold, and I was able to get my Access Point up and running again.
dd-wrt* - This is one of those projects for the true geek. If you have certain types of wireless router, you may download this third-party firmware that mods the routers capabilities. Truly amazing stuff can be done with enough brainpower. Check the list to see if your router is supported, and read the manual before doing anything that will void your warranty.
Free Antennas* - Want to boost your wireless capabilities without spending a lot of money? This site gives schematics and instructions for building your own antennas out of things like cake pans and even cardstock and tinfoil. Really, any smooth metalic surface will do. Very cool.
Hyper WAP* - Another third-party firmware, this one only for the Linksys WAP54G. Gives a power boost to your device while adding "a limited set of features to the last Linksys firmware, extending its possibilities but staying close to the official firmware."
Hyper WRT Thibor* - From the site: "HyperWRT is a GPL firmware project for the Linksys WRT54G/WRT54GL/WRT54GS and WRTSL54GS wireless routers based on the latest stock Linksys firmware. The original goal of the HyperWRT project was to add a set of features--such as power boost--to the Linux-based Linksys firmware, extending its possibilities but staying close to the official firmware. Over time, it has continued to be updated with newer Linksys firmware, and incorporated many more features typically found in enterprise routing equipment. "
Linksys Info* - Since I use several Linksys devices, it was only natural that I would stumble upon this very informative community website. Lots of smart people with probably too much time on their hands (thank goodness!) volunteer their knowledge for the common good.
Netstumbler* - For both wardriving and checking out your own network, this is a handy tool. It gives you all sorts of information about all the wireless networks available to your machine.
OpenWRT* - Open Source firmware written in modular form, so you can take the needed capabilities and leave the rest. Made for many wireless routers, it is basically a small, fast Linux distro that can give you the router you want.
Seattle Wireless* - Although this site is for a group of enthusiasts in Seattle, there is a lot of useful do-it-yourself hacking information for wireless networks, including hackinga access points and building your own antenna.
Third Party Firmware Comparison for WRT54G/GS* - As the name says, this is a comparison of the major third party firmwares for Linksys' often modded devices.
WiPeer* - Smart little program that allows to wireless-enabled computers to share files without needing any kind of wireless router or whatnot. True peer to peer networking. Was a student project.
Wireless.Gumph.org* - Not sure who is behind this site, but there is a lot of great wireless information, including ways to custimize and go beyond what you thought your wireless network could do. Makes wireless fun again.
WRT Routers* - Site devoted to the highly custimizable WRT series of Linksys routers, which can use all sorts of third-party firmwares.

Tech Support and Troubleshooting
Abbreviationz
Annoyances.org - Microsoft have been cursed for years as a result of the strange decisions, controlling practices and "features" (aka "bugs") in their Windows software. This site aims to help the user get around these roadblocks and annoyances. Very useful place.
Answers That Work
Bay Wolf Support Site* - Noncommercial site, done by one man, dedicated to helping those who have Dell Inspiron and Latitude notebooks. A great deal of helpful information here. Useful to me, since my laptop is an Inspiron.
Benchmark HQ* - Russian site (has English portion, too) that deals primarily with understanding the workings of your hardware. My favorite portion is the list of (mostly) freeware software tools.
Black Viper
Bleeping Computer - Community that aims to provide peer computer support. For beginners and more advanced users, too.
Boot Disk.com
Burn World
CD Freaks
Computer Gripes
Digital Media Guide
Dll Files
Doug's Windows Tweaks and Tips - The name says it all. Tons of info, even spanning back to Windows 95 and 98.
DNS Stuff.com
Domain Tools
Drivers Collection - Huge collection of drivers and firmware for a wide variety of hardware. Really a good source. Gives a complete description of the file you want to download.
Driver Guide - My former favorite driver site. Has a good selection, but has a lot of awkward navagation and now requires membership (I started using it when it did not). Ah, well. Still a good resource.
The Elder Geek
Error Forum - As the name implies, this is a Windows-focused site that allows regular users to post questions and equally regular users to respond. Nice little community.
Gibson Research Corporation
Groupworks
Hard OCP
I am not a Geek
The Internet Tourbus
IT Vibe
Kadaitcha - Windows XP Problem Troubleshooting Resources
Kelly's Korner - XP fixes
Langalist
Linksys Info From the site: "This site is a wealth of information to all users of Linksys Products or anyone looking for some networking help. It has been designed to enable users of Linksys devices to post issues and questions and allow other users to helpfind a solution with their products." The site is not owned by or affiliated with Cisco or Linsys.
Mike's List
MVPs.org - Directory site for a ton of people who are a part of Microsoft's Most Valuable Professional program. Each of the subsites have tips, links, downloads and more to help with you many aspects of Windows computing.
My WAN IP - Does one thing; tells you what your external IP address is.
Network Tools
No IP - This is a cool idea for those with always on connections. Want to connect to your home computer? Hosting a website, ftp site or game hosting from your own home? This will help you keep in touch with your home IP without having to remember the numbers, just an easy-to-remember name you choose yourself. Dynamic DNS at its best.
Old Versions
OpenDNS - Tired of your ISP's slow DNS server? Don't even know what DNS is? Try this free service and see what you think.
Optimize Guides - are free, easy to read, comprehensive guides for the Windows 2000, XP and Vista operating systems.
OS News
Outlook Express Tips* - Ways to soup up and speed up your Outlook Express installation, as well as how to back up and repair lost emails.
Paul Thurrott's Supersite for Windows - Tons of information here. Guides, tips, reviews and showcases of everything Windows/Microsoft.
PC Hell
PC Interfaces 101
Port Forward - Site that helps anyone set up their routers and understand port forwarding.
Ramesh's Site - Quoted from the site: "This site contains registry fixes, scripts, Troubleshooting Guides and freeware utilities to resolve problems in Windows XP. The resources available in this site should help you learn, diagnose and troubleshoot the common problems you face in Windows XP. Additionally, there is a section for Internet Explorer, addressing the Frequently Asked Questions in IE." Very useful site.
Scott Finnie's Site
Secrets of Computer Espionage
Shavlik - This company offers patch management for Windows, without the Windows Genuine Advantage garbage. Currently, they have a year-long free trial.
Smart Computing - A library of computer help, tips and reviews.
Tech Letters
Tech Recipes - Simple hints and tips for doing a lot of little things, getting the most out of your computer or consumer technology.
Tech Support Alert
Tom's Networking
Ultimate Boot CD
Ultimate Comuter Acronym Archive
Webopedia
Webstrider computer page
What is my IP?
The Windows and Macintosh Debate
Windows Secrets.com
Windows Secrets Winfind - Specialized search of 15 different expert sources to get the info you need.
Windows XP & 2000 Support Center - An unofficial support site for XP and 2000, run by James A. Eshelman. Seems to be very extensive and comprehensive. I found this while looking for a slow shut down problem I was having, but there are many other topics that will also be of interest to anyone having Windows problems.
Whois Source
World of Windows Networking
Xeniac gadget news