Some people think I'm obsessed with this game, to those people: YOU ARE RIGHT, SO WHAT?
Quake is the best game I've ever played (that's what I thought till I played quake II, but that's another story). There are countless QUAKE pages out there, and they're probably better than mine, what mine has over them is...well, nothing, but who cares?. I will put here a list of quake links, mainly ftp.cdrom.com (excelent site, but it's too known, and as such, too slow) mirror sites, as well as, of course, a link to the great Stomped Grounds, what could we have done without them...And, of course, the mother of all this thing: Id Software, I love those guys, and you should too.
Well, after those really good links (who didn't know them, anyway?), I will include a couple links to the descriptions of the two total conversions my cousin and I have in mind, have a look at them if you are interested in Warhammer 40000 or Space Hulk, and combining these magnificent games with magnificent universes, with QUAKE.
ftp.cdrom.com mirroring ftp sites
QUAKE Editing
Playing QUAKE is great, but even better is CREATING Quake. You will never be able to do that, sorry, only our God-on-Earth Carmack can do it, but you can try to imitate his doing with these little thingies...
Of course, there are lots of other editing utils out there for you to use, like unpakkers, or graphic programs, but I don't know the Homepage of none of them, so you'll have to look for them yourselves in the fine sites listed under ftp.cdrom.com mirrors.
GAMES WORKSHOP
They have nothing to do with QUAKE, and their prices are nearly unbeatable (you'll know what I mean as soon as you enter one of their stores), but they have created a Universe really full of death, and I love them for that. You may know everything there is to know about this Universe here.