The one stop shop for all your tweaking needs has updated it's Tweaking Companion guide. Actually shop is a bad word, since the knowledge your looking for is provided free by Mr. Koroush Ghazi over at TweakGuides.net. This was a good guide to begin with, so Version 3.0 is certainly welcomed.
"After many hours of revising and rewriting, the new TweakGuides Tweaking Companion Version 3.0 is out. It is now possibly the most comprehensive free Windows XP/System guide available. The entire layout has been rearranged to be much more logical and easier to read. There are links to dozens of new free applications and sites, tons of new advice scattered throughout the guide, existing advice has been refined or re-written for clarity, and importantly everything is up to date and accurate. I urge all of you to download it as soon as possible. Even for existing users there are gems of information all through this guide which you may not have seen before."