QUOTE (BIG BAD BEESTE @ Nov 25 2008, 12:32 PM)
Well, for maps I try to use real world atlas for geological data and then cross reference it with my library of SR books. That can leave me a little short for detailed combat area maps however, so I either whip out a quick sketch or use those ones from my old DMZ set. Sometimes I even draw up a nice detailed floorplan in advance - but my players have a knack of by-passing those locations.
For real world references though I've found that having a bash at Google Maps can be really helpful for foreign locations (IE Northwestern America for me) as it also has street/sprawl data. Far more convenient and up to date than my old Rand/McNally hardcopy handmap of Washington state.
Hmmm, come to think of it if you're running in the UK then checking out the Ordnance Survey maps should really give you some detailed terrain maps. As for floorplans & buildings - well, I've always relied on my draftmanship training and getting out and about physically. Nothing can beat some real life legwork and a grounds eye perspective for a realistic environment description.
Quick sketches are good. I usually base things off of building I've seen or been in so that i have a more viceral understanding of the layout and can it explain it to players. That can make building seems a bit antiquated but if no one's asking about energy pylons, or AR overlays on this or that floors in specifics than it works out well.