Even before doing all the work of finding property, checking on zoning, etc. I would gather the data for residential sales, pending sales and homes on the market for sale. Any real estate agent can give you that (their Multiple Listing Service tracks it for them) then I would segment the data into $15K pricing increments. This is what you are looking for:
1. Define size of each market segment - Number of units sold, dollar values, absorption rate (avg. time it takes to sell)
2. Size of homes (sq. ft.) selling at a particular price point.
3. Look for a gap in the market where the demand exceeds supply.
4. Identify housing style, amenities and newest construction practices for today's buyer.
*5. NOTE: Do not choose to build in any market that any one builder owns 50% of.
I have done this in every market I have ever developed in and have never built a house that wasn't sold 30 days prior to occupancy and I build in the spec end of the market. I let the market tell me what, where, and how quickly I need to build a project.
When you assemble your game plan (business plan) with information as detailed as this it is very valuable and you should not casually give it out. Treat the information as talking points (I even have had Realtors and builders try and by the info from me) until you identify all the players on your team (I mean a builder, agent or others you may want to work with). The reason your newly assembled and correctly interpreted data is valuable is because it is bankable! You have minimized the risk by removing much of the speculation in real estate.
The knowledge you have about your market is by far more than anyone else has. Recognize this and don't second guess yourself - builders, Realtors and others in real estate may have more years experience but you KNOW the market.
Good luck!