The purpose of having the kids participate in a Young Eagle Flight Rally is for them to have the meaningful flight experience in a small airplane.   More information about Young Eagle Rallies can be found at www.youngeagles.org.
The approach that I have taken to having a group of kids participate in a Young Eagle Flight Rally is to coordinate this with the local chapter of the Experimental Aircraft Association, EAA, as to when they can do it.   One way to simplify the participation in the Young Eagle Flight Rally is to schedule the kids as group.   This minimizes the time needed for the whole group to go flying and increases the odds that the kids will get to fly with other kids that they know.   Finally, demonstrating a flight from your local airport via Microsoft Flight Simulator is a good way to communicate to the kids what they can expect from going on a Young Eagle Flight.