Firefox Tweak Guide At TechSpot

TechSpot.com has an extremely robust tweaking guide for firefox, that not only deals with firefox's standard settings, but also deals with Extensions (with quite a few recommendations I use myself), Themes, and yes, even the hidden advanced settings in the config files. It's quite easy to follow, and even has pretty pictures to help ya through it, should you get lost along your way. You can find it here Firefox Tweak Guide - TechSpot