I'm a total newbie at making maps. I've collected up some textures and pieces and parts, from other sites. But I don't know how to put it all together yet.

I'm wanting to build an entire campaign around a large city arena, with multiple competing guilds. Only I will need a HUGE multi level arena, and the guild halls around it, to pull it off.

So I'm looking for
IDEAL: Someone to create a starting point for me, and teach a method to wash rinse and repeat so I could finish it myself.
SUFFICIENT: Examples of others work that is similar.