Depending on the age of your child(ren) you might also want to consider the babysitting services offered at the resorts like the Polynesian's Neverland Club, the Swan/Dolphin's Camp Dolphin, etc.
We used Camp Dolphin in April 2001 and I can't say enough positive things about their services, or the people they employ. Thelma was wonderful, and she remembered us when we returned a year later!