Your research questions should revolve around the demographic data of your customers such as age, location, and income (what they can afford). Your research should also address larger questions such as what type of demand there is for your product, how you might generate demand. In addition, you will want to find out how many competitors provide the same service or product and whether you can you effectively compete with regard to price, quality, and delivery.
You also might want to ask yourself whether you can price the product or service so as to assure a profit. Finally, it is helpful to understand the general economy of your service or product area and the areas within your market that are declining or growing.