The Planning Board is responsible for reviewing all subdivision applications and larger development proposals requiring site plan review. See the Land Use Ordinance (Chapter 145 of Town Code) and Subdivision Ordinance (Chapter 202 of the Town Code) for more information on requirements and processes.
The Planning Board also participates in overall planning for the town and is involved in all proposed changes to the Land Use and Subdivision Ordinances.
They typically meet the 1st and 3rd Monday of the month. See meeting calendar here.