Pediatrician process


So getting everything ready to be pre-registered at the hospital for our delivery in May and the paperwork says that we must find a pediatrician for the baby before coming to the hospital I found a medical group that I really like it has come highly Recommended by friends. How do I go about notifying the doctors office that I would like to use them as a pediatrician? Do I just call the office or do I have to set up some sort of visit with the pediatrician before the baby is even here? Any advice with this process would be greatly appreciated!