Since I didn't have that much 3D knowledge, I kept things very simple. Most of the objects started out as a box and then I proceeded to pull the edges/verts, cut, extrude (basic polymodeling tools). Only a few objects use Meshsmooth modifyer. What I decided to do is to use Tessellate modifyer instead and on top of that a small amount of Noise modifyer (as we all know, there are hardly any surfaces that are dead straight).
As this was the focus of my scene, I modelled it first. I got the reference material on the net (Google Images). Frame was built first. Then the door - copied 4 times and at the end I did the top part. This is one of few objects that use Meshsmooth.
I had to decide here, if I want to use bump mapping or model them. I went for the latter. I created a plane with enough length and width segments, selected all polygons and extruded them. Then I put some modifiers on top (noise #1, tessellate, noise #2 and uvw mapping).
Buildings... well walls were made out of planes. I extruded the polys where the windows are inwards and that was that. All I had to do is to add a few more edges so that noise modifyer could do its job and I was done.
Take 3 triangles, bend them and then randomly rotate&scale them. The rest is just copying and positioning.