Personal recommendations are usually how people find their dentists, I'm not sure there's any better way. Ask several colleagues and friends to talk to you in depth about their experiences. Make sure you ask if they recommended extensive expensive treatments, routinely recommending such treatments is a bad sign the dentist is doing unnecessary work for profit (which happens). Don't hesitate to call up different offices with any questions you may have. If they won't or can't answer your questions they aren't worth your time. Don't hesitate about getting a second opinion if you're not sure about their treatment plan.