The baby centers are awesome! There is a kitchen with polar water and one that is hot for making fomula, you can buy almost anything you have forgotten there, there is a dark, quiet, private room with rocking chairs for nursing, There is big room with changing tables, they have a bathroom, a place with high chairs to feed older kids, and they have a room ( sometimes with the highchairs) with a tv and stuff for siblings. We used this all the time when my son was 3 months old.
Mgm's is located right inside the main entrance and to the left, right before you hit any stores. Its in the Guest Relations building right across from that kiosk right in the middle where you get your locker keys.
Animal Kingdoms is on Discovery Island adjacent to the Creature Comforts store.
The other poster was right about MK's being next to Crystal Palace and Epcots being in the Odyssey building between Test Track and Mexico.