Hey.
I'm not too sure about the multiplayer servers, I've never tried, but it would be best (if poosible) to use another PC to host these servers. That would make it a dedicated server, and is much faster. Or you could make one that you play in as well, although it would be slower. Like I said, I have no experience with this.
As for the map making, I'll tell you where to start.
Map making is very complicated and hard to begin with, but as you get used to it, it becomes very fun and easy. You need the program, first of all:
GtkRadiant 1.5.0: The actual map making program
http://eliteforce2.filefront.com/file/GTKRadiant_150;62263
JK2 Editing Tools 1 and 2: Just some useful tools like modeling and scriping, and contains some components for Gtk.
http://http://jk2files.jediknight.net/file.php?id=950
And part 2:
http://http://www.richdiesal.map-craft.com/tutorials/lfn-JK2EditingTools2.exe
Install these to your Jedi Outcast/Gamedata directory
Now, these tutorials will give you all the necessary help you need to get you started:
http://http://www.richdiesal.map-craft.com/tutorials/
Although it is for JK2 Radiant, nevertheless it is a very helpful site.
Hope all that helped, if you have any more questions, ask them.
Time2Die
I regret to inform you...
Time2Die!