Org - It's the only decent site I could find about the game. This game also rocks in single player mode, and it is also the most popular multiplayer FPS right now. Enemy AI is pretty good, and the game looks really nice for the time it was released. Planet Half-Life might be a good place to look for help or mods. Here's some spraypaint logos I made back in the day.
Trip mines are cool.
The Quake series Arguably the game series that took online gaming to a whole new level. Try not to laugh too hard at the HTML coding and the gross backgrounds. Do so here. I was on the OGL for a while. I left due to lack of interest in Q3A and the level of inactivity at the time.