I'm having problems trying to build the building. I can't seem to build it right for some reason.
I'd start with a foyer, like a place to "check-in/out" the kids.
Then a nursery for the babies and toddlers to sleep/ be fed/ cared for.
Also, add a toddler play-room for their toys: doll house, play tables, xylophones, stuffed animals or anything else to keep them entertained
(I'd also include a sterio for the extra "enjoying music" moodlet)
Make sure to make a play ground outside for children: swings, slide and jungle-gym. (also include a trampoline if you have ambitions)
Make a cafeteria if you want, though it is not nessecary, make it a room of it's own but replace one wall with a bar to eat at.
Don't forget bathrooms! Use the "private" stalls so many people can "go" at one time.
Hopefully this more helpful than before! Good luck!
EDIT: For the cafeteria I meant not an open area like 3 full walls, and the 4th side could be a bar... If that makes more sense.