Just a few advice, I posted this at happypenguin as well:
A small guide for newbies to quake on linux

:
To have a complete installation of quake which you can play online use
eQuake.
eQuake is a compilation of textures, huds, mods and whatever there is for QW.
The client used by eQuake is
Fuhquake which is one of the 3 preferred clients nowadays.
FuhQuake also enables you to play singleplayer if you want that.
For info about quake and what's going on today there's no better site than:
http://www.quakeworld.nu
There's also eZquake as well as mqwcl (which have ceased in development, but still is a good client).
Tenebrae and such gfx heavy clients aren't really used by players who compete or play online, but hey download and try them as well if you want =)
For further help with quake on linux I can recommend these forums:
http://gibbage.mine.nu/forum/
http://www.quakeworld.nu/forum/
For quick downloads of clients etc you can always use
http://gibbage.mine.nu.
Also check the links from
http://www.quakeworld.nu to other sites.
If you want to see how players play today or simply download demos to quake there is no better place than:
http://www.challenge-tv.com/
Well I hope it helps. I know it's not QuakeForge info. Then again. I don't know of anyone that plays quake seriously and actually uses QuakeForge