I can't recommend a school, but "Joe Cool Taxi and Tours" will take you to one for free. http://www.joecooltaxiandtoursjamaica.com/

We're using them for our transfers, and to do the school visit (bringing a large bag loaded with school supplies and stuff).

I'm told that its quite important not to just drop in unannounced - causes chaos in the school.

Hope this helps!