After just having undergone a less than pleasant experience with a new provider (an NP) I would say do as much research as you can. Read the website bios (even though they usually don't tell you much) and talk to people you know. If you can actually talk to the doctor before decide to get an idea of his/her personality, I would say that is the best.

I would also say think about things that might matter to you: gender, availability of appointments, approach to care (are they open to alternative treatments if that's something you are interested in), office hours. Also check which hospitals they are affiliated with. This might depend on the type of insurance you have.