Along these line of thinking I think making resource maps would be beneficial. You might need more than one map for the same area to keep them from being to cluttered. I have yet to make my own but have been thinking about one map for raw materials, quarries, and bulk items like coal. Another for finished goods, like every pharmacy & agro supplier, etc.
On the mill, water was always the power of choice in the past. If your group does use water, take the flow from the bottom of the pond with a pipe into an enclosed turbine/wheel house. Then your mill wont freeze up as much in the winter. Sturbridge Village has 2 working mills that would be good study pieces. Using modern bearings, shafts and grears should make building one with good efficency pretty easy.