This guide deals with how to feed your markets/stores using belts.
When I began playing Factory Town I had trouble figuring out how I was going to feed all my products via belts into the market/general store (or any other store!) until I realized one important thing: stores don't need to be fed from their "ground level" only.
The back side, where products are fed:
The front side, where the road connects:
This setup allows for feeding up to 10 products at Y-level 6 and 8 (aka 6 and 8 levels from the ground). The build is raised 6 levels up above my houses/production facilities to make it easy to move products around. The upper belts are supported using arches to allow movement of goods beneath. The road spirals below the beltways to connect to your houses.
There may be more efficient ways of doing this (I'm only a little ways into the game), but this build supports early through mid-game setups easily.