Here's a scene I set up about 10 years ago.  It's a nursery room, in which Skipper is attempting to babysit 3 children, including twins and a litle girl. 

This scene was set up simply enough with a contact paper border cut from plaid elephants that I overlapped into a follow the leader type pattern.  It covered up some of the imperfections in the dollhouse that housed this scene.  I used contact paper elephants and some movie posters depicting childrens' movies to add some random character to the walls.. 

The room furnishings included a cardboard shelf which came with a Barbie or other playset. The chest of drawers was constructed from matchboxes that were glued in a vertical arrangement.  The sink and crib were included with Kelly dolls.  The rocking horse and toy chest were purchased unfinished from a discount store and painted white.  The rest of the miniature toys were purchased in Micro Machines, Polly Pockets and other miniature toy sets. 

The carpeting is easy to aquire. I found a carpet store that left its scraps and remmants from installation jobs in a bin behind the store.  These are the perfect sizes for scenes and dioramas.  The scraps are easily cut with a box cutter, but use caution!