The kids and I have hiked almost all the trails numerous times. It is a great outing to spend time with the kids.
-- Bring a lunch and have a picnic at one of the parks picnic tables.
-- Meet other people on the trail. The kids have meet numerous other kids hiking. It is amazing to me how easy it is for kids to say HI and have a friend almost instantly. I wish it was the same for adults.
-- Bring LOTS of water. There are no fountains on the trails - and being without water is like a death wish. We usually carry an extra bottle for the poor soul that we see without water, it happens on every hike. Don't under-estimate how long/hard the hike is. Be prepared!