Asking about their problems or goals is the best. In other words, don't ask about what features they want (you'll figure that out), but ask what their goal is.

Asking about their problems or goals is the best. In other words, don't ask about what features they want (you'll figure that out), but ask what their goal is. Research is good, especially in helping you figure out what questions to ask and getting close to the issue, but talking to potential users is unbeatable. I'd highly recommend 4 Steps to the Epiphany for great customer development guidance.