This post isn't really something to be read, but it's just a summary of essential informations about Quake 4. It tends to compile every useful things that I could find about this game here and there.
Of course my article isn't the first attempt of this kind made so you will find links to some older articles/guides as well.

So here is what you have in this article:

1 - Files you may need:
- Patches
- Maps
- Mods
- Server browsers and tools
- Misc.

2 - Guides and useful links:
- Guides
- Strategiy guides
- Q4 related IRC channels
- Leagues/tournaments
- Useful (or not) links