Just about all the information you can want to find about Quake coding can be found on the . It's not limited to QuakeC stuff, though that's included, it also has engine coding, mapping, and other information.
Of course, as I'm posting this, that website seems to be offline, it should be back in a while.
As for a compiler, the most popular seem to be FrikQCC and FTEQCC. http://www.inside3d.com/frikbot/projects.shtml