The goal is the education process in the journey, not the destination. Tell everyone, including yourself, that we are going to make mistakes. No one can learn without them. Wherever possible, let students that have a spark of desire to try their hand in the artistic process. Get older students to return to your school to help with stage managing, choreography and direction. Grab choir, orchestra and band students to involve them in the show. Most importantly, allow what is created to be their own.
Perhaps the biggest tip for success I have learned is making the entire production process as organized as possible. Using shared spreadsheets (edit rights for anyone with the link) on Google Docs makes it easy for all of the parents to sign up to chaperone, fill in conflicts, be on a committee, budget and anything else that is needed. There are other tools out there but Google Docs is second to none in shared management of information and can work with whatever electronic device an individual is using. Create a group mailing list that all parents can use is also important to facilitate communication.