If you are bringing a stroller ask for a gate-check. This means the stroller is taken from you as you board and given to you as you deplane. Never check your stroller with your luggage. You will need a stroller for the long walk to baggage claim or for changing aircraft. If there is time, ask the flight attendants if it's possible for the kids to get a peek into the cockpit before or after the flight.
Most flight crews enjoy showing children the cockpit.
More often the best time is after the flight. Kids will be amazed by all the lights and instruments. When in your seats explain to the children about the fasten seat belt sign. Let them know when the captain has the seat belt sign on they cannot leave their seats. Let children take turns at the window.