Reference and Documentation
Art Development
Textures/Matrials
ShaderManual (very important reference)
Sound/Music
Modeling
Level Development
ConfigureXreaLRadiant
Game Sample Programming and Objects
External Links
KatsBits - modelling, texture, map editing tutorials, tips and downloads
Game Modelling Tools & Utilities - useful tools for XreaL content creation
The Art of Level Design
Common Sense vs Level Design
Creating Normal Maps with ATI Tools
Other interesting Doom 3 engine editing sites
www.doom3world.org - The premier discussion forum for all Doom 3 engine games
www.iddevnet.com - The official id software website for Doom 3 engine editing