Create Google maps
http://www.google.com/intl/en_us/help/maps/tour/#create_a_map
Add content to Google maps
http://www.google.com/intl/en_us/help/maps/tour/#add_content

My Maps (create new map) http://maps.google.com
Map Builder http://www.mapbuilder.net

Map My Page http://www.mapmypage.com

Sample Maps:
Boarding Schools http://www.boardingschoolreview.com/map/type/3
World Heritage sites
http://clement.beffa.org/labs/apps/worldheritage/#au