I've actually had a couple of requests recently to help out with modding tutorials. I'm really only moderately skilled at coding, and not good at modeling or mapping at all, but I can point dudes in the right direction. insideqc.com and quakeone.com have lots of good info on modding and mapping and whatnot. go to the forums.
Coding
QuakeC Manual
QuakeC help at insideqc.com
QuakeC Help at quakeone.com
Mapping
Func_msgboard
GTK Radiant
JACK Editor
Modeling
Noesis model converter
Misfit model can attach skins to models so you can convert to quake model with other software
blender 3d is great for modeling but don't ask me how to use it
Very cool i suck at these things, but maybe in the future!