J.G.
Chiming in with what was already said, I would check out the Troy schools programs.
www.troy.k12.mi.us/elementary/preschool.htm
I know several SAHM's that also use the Troy co-op preschool.
www.troycooppreschool.com
Another school that I really like is Japhet, which depending on where you live, might not be too far.
www.japhet.org
Other schools I've heard good things about, or liked myself:
Birmingham Community Montessori- www.bcmpreschool.com
Spanish Immersion Montessori- www.spanishfortoddlers.com