How did you paint up the buildings? Do you have a tutorial?
Did these back in 2008, and I don't think I have a tutorial, but I do remember how to do them.

Prime the buildings white. Get a dark chestnut stain from the paint/diy/home store. Cover the whole building with the stain and then take a rag or towel and wipe the stain off the surface, allowing it to remain in the deeper areas. Even wiping off the stain, it will have changed your white prime to a dirty white. Then, drybrush with an off-white.
Paint doors and window frames with your personal choice for doing wood (mine happens to be a dark brown with a single lighter brown highlight.)
Any exposed bricks get a touch of clay brick or any reddish brown color.
The roofs are the only thing I can't tell you exactly on. I picked up a terracotta textured spray paint for them. Then drybrushed with a burnt sienna/white combination.