Ask HN: Tips on writing a good survey for market analysis?

I've got an idea for a business, but due to some regulatory concerns, I want to suss out the viabily of the business before investing too deep into it. This is a B2C business.

I'm thinking about setting up a booth in a few malls and conducting some surveys with people. Is there any tips/resources/books on writing/asking the right questions to get the most amount of useful data?