I'd keep it short and sweet but sincere. Thank them profusely. Maybe share a few statistics about what their efforts helped provide:
Maryvale Volunteers are the best!
* $xxx was raised.
* X (#) of volunteers provided Y (#) of hours
* ### students went on fieldtrips
* ___ was added to the playgorund
* ### books were put on the library shelves
Fun stuff like that. Then be sure to mill around and chat with as many people as possible. Encourage your board members to do the same so you don't congregate at the same table/area. Make it clear that you're
all on the same team working together, not that
they helped
you be successful but rather that
you all helped
Maryvale PTO succeed.
Sounds like fun! If you have any leftovers, pop into pg2 afterwards.