We went to Beaches Boscobel 2 1/2 years ago. My boys were 22 months and 4 years old. We went with my dh's family, so there was also a 7 year old and a 10 year old. Everyone had a blast!! There was plenty to do for all the age groups. My little ones LOVED the Elmo theme, and the older girls got to snorkle and other activities for older kids. They had a cool "family" pool with a great slide and a big baby pool (which we only used once) It is a very child-oriented society, so the childcare was exceptional. My older son has some autistic-like traits, so we hired a "nanny" to follow him in some of the activities that took them out of the childcare area (they only do this for 2-or is it 3? and up. My dh and I were able to watch them a couple of times without them knowing and the were very patient with him!! Oh yeah, the food was pretty good, with a special buffet for the kids.
Anyway, it is a great place for families. The only thing we would do different is go to the one that is closer to the airport (I think it's Negril). That one is supposed to be nice without the 1 1/2 bus ride to/from the airport. That being said, the ride wasn't near as bad as we anticipated and they were all very accomadating. We felt VERY safe at the resort, and didn't feel the need to leave with all to do on the grounds.
My husband and I went to the Sandles resort in Jamaica for our honeymoon. We loved that also. It was a little more classy with more upscale food, but that makes sense since it's for couples only!! Did I mention all the drinks are included at both resorts? I LOVED all the fruity "adult" drinks :)
Let me know if you have any specific questions!!