1)Is your contractor reliable? I can't count the number of friends that I have who have had problems with contractors. Kitchen remodeling is no different. If you hire a contractor to redo your kitchen, make sure they come with great references from uninterested parties. There is nothing worse than have a kitchen that is only ½ way done after the contractor decides to disappear midway through the job.
2)Is your kitchen so complex that you will end up paying a ton of money? We know several people who had unrealistic expectations before getting their kitchens remodeled. They either ended up with a kitchen that wasn't as nice as they wanted or they ended up paying through the nose. Be realistic about what you want and what you can afford.
3)Are you informed about the kitchen remodeling process? Without knowledge of the kitchen remodeling process, points #1 and #2 aren't really all that important. Like everything, there are tricks and tips to make sure that your project comes out looking fantastic while not paying too much money. The insiders know exactly what to do and what to say to make sure that their project turns out looking like the kitchen of their dreams. Get informed on the entire process before investing your time and your energy on a kitchen that doesn't turn out how you want it. It's not that hard to learn, but learning about kitchen remodeling is well worth your time.