Okay, been away from the forums for quite a while. I'll try to address some questions in case people are still checking in.
RipperX:
Are you running Vista? I know some other people have had troubles with saving maps on Vista. If so, try running Warband as an admin when you edit and see if that helps. Otherwise, I'm not sure how to help you, but check the Taleworlds forum.
ToxicKilla:
I've noticed that ladders won't function properly until you exit edit mode, exit the map, and reload it from the multiplayer host menu. Have you tried this? This is generally a good thing to try anytime something you've just added isn't working but should be.
Darkwulf:
If you want friends to try your map, they basically need a copy of your "mod." Archive your mod folder and send it to them. When they run the mod they should be able to try the map in multiplayer by hosting a game for themselves.
Vagabond:
I think you can just rename your mod "Native" and swap it in for the Native folder already on the server. Back-up the old Native folder first to be safe. Then people running native should in theory be able to join your server and play the custom map. I'm not positive on this one though since I haven't managed a server in a while. Find Airith on these forums, he can help you better than I.
Spike:
If you want it on the cRPG server's, post it in the completed maps thread and they can tell you what to do next. If you want to host it yourself in Native then you should basically follow my advice to Vagabond.
I'm glad the guide is proving helpful to people. Hang in there and feel free to ask more questions (especially if my answers were too short, it's late).