LINKS:

EDGE HOME
Edge is a good engine for FPS games.

Lobo's Robotech First Gen site
A good site with many tutorials and tools for EDGE developement

Nick Perrin's Site
He's the developer of Marines Of UAC another great EDGE mod

WadsInProgress
A database of Doom related mods maps and conversions

WildWeasel's Doom Armory
A site for weapon modders