Balance. I hate maps that are biased to a particular team.
Open-ness. Not so open that it's a flat playing field, but rather something like dust where you've got lots of room to move, as well as a couple of nooks and crannies.
Detail. CS is supposed to be somewhat realistic. Make sure your mapping reflects that.
If you wish, I can give individual comments to each person who entered. I can do this via email: if you want a comment then post here and I'll email ya.
Watch out for those updates. If you don't want a game to update, right click the game, go to Properties (in Steam) and select "Do not automatically update this game". That, or be patient.
Now, I wouldn't exactly condone having drivable trains in CS:S, since it'd be useless in a game. Your choice however. I reckon an undrivable train that runs on a track might be better. If you get stuck, post your problem and I'll try and help. They can be a bit bitchy at times (the trains that is).
Make a brush based train and make it a func_tracktrain. Check out the options (the flags in particular) for how to make it a drivable one (I think its the "Half-Life Train" one). You'll need to use path_tracks to setup a path for it.
Well, after consulting with Alex, here they are! The official compo results. This will obviously appear on the real page when Atom gets a chance to do so.
WinMX is good for dial-up. Unfortunately, it's hopelessly outdated now. I use SoulSeek and WinMX for p2p and Azureus for torrents. Shareaza is too nooby imo.