Ask Your Obstetrician
If you're not sure where to begin, ask your obstetrician if she has anyone she'd personally recommend. Oftentimes, there's overlap in the medical community, and if you're pleased with your ob-gyn's practice, they may be able to refer you to a like-minded pediatrician.
My obstetrician actually had a list of recommended kids' doctors broken down by neighborhood, which is how I found my son's pediatrician, and something that I've since shared with several friends. It's worth an ask!