A.R.
Have you tried the website angieslist.com? It is a referral and feedback site for contractors of all kinds. At the very least it will let you check out a contractors reputation. I would also suggest meeting several concrete people and getting AT LEAST 3 quotes. More expensive doesn't mean better and cheap doesn't mean bad. Definitely ask to see previous work. If they can give you actual addresses, even better. We recently had a deck built and a patio laid and stoned and my husband did all those things and still had to watch them to make sure they met the standard we expected. I wish I had the concrete guys name for you, but my hubby is out of town and doesn't know where he put it... If I find it I will come back and post it. He did a great job. HTH
A.