Bunny-hopping guides:
Bunny Hopping Made Easy by [ ]_ziGzaG
Bunny hopping by Joop
Lost CS Bunnyhoping Guide/Interview

Counter-Strike stuff:
Whisper's Counter-Strike War Strategy Wiki
Tickrate - Whisper's Wiki

HLDS resources:
Guide: Setting up a Standalone Dedicated Server
Managing HLDS Server Resources
Optimizing a Dedicated Server
The Valve Developer Community

GUIs & stuff:
The CS GUI's ultimate guide
CS v1.6 GUIs on FPSBANANA.com
CS v1.6 GUIs/Sprites tutorials on FPSBANANA.com