Here are my main links. I have another page of lots of links HERE
 
Official
Epics Unreal Web Site: Official game website for Unreal
Epics Unreal Tournament Web Site: Official game website for Unreal Tournament
Epics Unreal Technology Web Site: Latest news on editing, patches etc, get it fromt he horses mouth here...
 
Getting Help
Fordy's Unreal Tournament Site: Lots of downloads and other useful information - check this one out.
Developium: An emerging repository for game developemtn in general
 
Editing
Lode's Unreal Zone: The best lighting and mover tutorials ever!
Unreal Tutorial Database: Database of tutorials
UnrealEd: one of the biggest editing sites
Wolf's Unreal: One of the best and most thorough beginner UnrealEd tutorials I found
Unrealized: Alternative to UnrealEd, with a "Ask the Expert" approach
Fleshdance: Word downloadable Unrealed tutorials! Cool!
Clan Co30: They have some good tuts going up lately
Unreal Academy Web Ring: Another Unreal Editing Web ring
 
Pathnoding
Pathnoding Tutorial for Unreal: Good pathing tutorial
Schlacht's Pathnode Tweaking Notes: Good for working out what make GOOD paths!
 
Utils
Milkshape 3D: Awesome (and cheap) 3D editing tool
UMod Wizard: a tool for making umod files, doh!
UTilities: Some very usful package editing tools
UT Toolkit and Tool Forum: The UT Toolkit and a tool creation forum