APTA: Maine Transit: Information from the American Public Transportation Association.
Chebeague Transportation Company: Provides ferry service to Chebeague Island, Maine. Schedule and fare information available here.
City of South Portland Bus Service: Bus service throughout the city of South Portland, Maine. Schedules, fares, and route maps available.
Cooperative Alliance for Seacoast Transportation: Provides bus service between New Hampshire and Maine. Information on schedules and fares.
Shuttlebus-Zoom: Large bus company operating in Maine. Site has extensive information on all lines, including schedules, fares, and maps.