Ayer information from state agencies:

Community Profile (DHCD) (PDF)
Ayer Public Library Information
Ayer School and District Profiles
Community Preservation
Helpful Telephone Numbers
Local Area Unemployment Statistics/Employment and Wages
Massachusetts Department of Education School listings
State Aid - Cherry Sheet FY2004
State Aid - Cherry Sheet FY2005
State Aid - Cherry Sheet FY2006
State Legislators
Valuation (Real Estate) certification statistics (PDF)

Regional information from state agencies:
Hunting, Fishing, Trapping License Vendors
Montachusett Regional Planning Commission
Regional Centers for Healthy Communities
Regional Hazardous Materials Response Locations
Southern Middlesex Registry of Deeds
State Police Troop

Information specific to Ayer can also be found within the following comprehensive listings:

At-A-Glance
Department of Conservation & Recreation - Urban Parks
Department of Mental Retardation Area Office Locator
Department of Public Health District Offices
Division of Career Service/Division of Unemployment Services (DET) Service Centers
Division of Fisheries and Wildlife District Offices
Division of Marine Fisheries Offices
Find your Watershed, Executive Office of Environmental Affairs
Health & Human Service Resources
Massachusetts Office of Travel and Tourism
MassHighway District Offices
Private Counsel Bar Advocate Contract Offices
Public Defender Offices
Regional Centers for Healthy Communities
Registry of Motor Vehicles: Automobile Inspection Stations
Registry of Motor Vehicles: Branches
Registry of Motor Vehicles: Motorcycle Inspection Stations
Search for Your Polling Place, includes Ward, Precinct
State and National Crime Data
Veterans' Agents, Department of Veterans' Services
Wellness Data