Choosing a pediatrician. What do I need to tell them when I call?

Kind of a stupid question but I think I have a pediatrician chosen. Alot of ppl recommended her saying she was the best in our area and then I went with a friend of mine when she took her baby and she was very friendly and I liked her alot. I just made sure my insurance was accepted at her office and it is. I am now getting ready to call and to let them now i'd like her to be our pediatrician i'm just not sure what to say when I call?