lol, tuts are not really my thing, but other people have posted some already on this fourm...and they are alot ALOT better then me at mapping.
If you need help on mapping, just post a topic somewhere and have a screenshot of your map, I can point out some problems, and better ways you could make the map.
Somethings i like to do in my maps, is make each unique like this one:
Notice at first look its a normal house, but look behing the right bookshelf, there is a hidden passageway! using events on action button the bookshelf splits open revealing the passageway.