JCC Manhattan

Jewish Community Center in Manhattan http://www.jccmanhattan.org
334 Amsterdam Avenue at West 76th Street
(646) 505-4445
Classes for all ages. Expecting parents, prenatal, new parents classes and moms groups. Beautiful pool, nice warm kiddie pool. (You don't have to be Jewish to join and enjoy their facilities.) Tons of kids' classes, and they have childcare for $8/hr when you want to exercise. Or, for those days you really need to get out of the house, for $5/hour you can hang out with your kids in the babysitting playroom.