What is the best strategy to find an excellent dental practice for veneers and implants?

I am starting the process of looking for someone who can give me veneers on my front four teeth which are already largely composite due to an accident i had. I have no idea how to tell who will do a good job and who wont... or what a fair price is. I have read that before and after pictures are important but if there is anything beyond that then please tell me. I was thinking restricting my search to a certain geographical area like Los Angeles might help too. Any help is much appreciated.