Yes - and also try Angieslist.com. Real reviews - and the ability for an open conversation and comments from the company to balance out the information to make it fair. Then ask for some references to at least 5 customers in the past year. Ask pointed questions: Did their original bid cover the work, or were a lot of change orders and extras added on before you were done? Did they communicate well and approach potential problems in a teamwork, even handed and easy to understand way? Did they show up and complete the job in the timeframe agreed upon? Did you ever feel that they had you "over a barrel" and meant to take advantage of the situation, or were putting your job behind larger "more important" ones. In the end, would you use them again, or look around before hiring someone for the same type of job in the future?
Do check licenses with your local State Contractors License Board. And finally, if they are currently working on a project, ask if you can see their finished work in person. Often this is possible.
Good luck to you!