We own a 30' sailboat and we really enjoy it. Our daughter was 3 when we got it, so we had to teach her to "stay safe." When we would tack we'd say "Stay Safe" and she'd go to our designated spot on the boat and hold on to the rails until we told her it was ok. That way, when my husband needed my help, we always knew where she was and we could take care of the boat in rough waters, etc. I would advise anyone with young children to do this.
As far as maintence, I only know that once every other year you should take the boat out of the water and give it a bottom job. My husband putters around on the boat, washing it down, polishing, etc. But it doesn't need lots of maintence.
We've had our boat 5 years, and we love sailing it so much that we'd like to get an even larger one. We've anchored it in the bay and camped on it for a weekend, etc. You get away from the hustle and bustle of everyday life, plus you bond as a family. What can be better than that?
D. C