Here are some texturing tips:
Hold down ctrl + alt and press a face (side) on a brush (wall/floor/ceiling) to add a texture to that face.
Hold down ctrl + alt + shift to then apply the last used texture to a face.
Press S with a face selected to move/scale/fit textures to a face.
I think that's about it...
Great work! Try adding some more themed eye candy for the next version as well, but otherwise, awsome map!
