Repeating What Kell Said In Detail.
Yes Saturday, at 4pm Eastern Standard time. Timelimit is 100 mins, but it's loosely enforced. No, it's not SP only, but most people have been making SP maps for these last few themes. Speedmapping almost always is open gametype, unless theme dictates otherwise. There IS a website, but I've not bothered to work on it/get it proper done. http://speedq1.spawnpoint.org/
is currently just a mirror of Paul's older speedmap site and packs. I'll be getting it together soon. Of course you can enter a map, either join the IRC channel at #speedq1 on irc.gamesnet.net at the time of the live event, or email me a map at email@example.com . This week's theme is going to be Episode 4/Elder World, as the last 3 weeks have been the other episodes of Quake. Starbuck or myself annouce upcoming events every Weds/Thurs in the General Annoucement thread, so watch there in the future.
I'd wager to bet your underwear WAS white, but is not yellow from excitement now that you know how to enter the speedmap event!