You've launched your startup, you've probably pinned down some investors, and all signs point to a "real" business. However, you are just getting started. Every time you add someone new to the team, they're a new "moving part" and can either make the environment better or worse--though in many cases it's a little of both.
Mosts startups like mine are on a tight budget and can't afford to hire the wrong person. Others, particularly with founders who consider their business their baby, want to make sure the person they hire is a right "fit" for the company. After all, if you're going to be working with a person closely for most of your waking hours, you want to like them and make sure you're on the same page. I'm in the middle of the two!
Here are a few must-ask questions for a business owner hiring a new team member. These answers will tell you if the person complements you business, if they're in it for the long haul, or if they'll just say yes to the first outside offer they get.
End each interview by asking what the candidate likes to do outside of work. You both love to kiteboard on the weekends? That might tell you a lot more about company culture fit than any other question.
Most importantly, actually follow-up on references and trust your gut. It rarely leads you astray.