Google Maps Icon http://code.google.com/p/google-maps-icons/

Map Icons Collection is a set of more than 900 free icons to use as placemarks for your POI (Point of Interests) locations on your maps. You can use them on Google Maps with the "My maps" feature, or automatically by using the Google Maps API.

Organized in logical color coded categories for better and quicker overview., you get a complete and diverse collection of unique markers for point of interests like cinemas, bus stops, banks, Italian restaurants and shoestores.

He is the author of Beginning Google Maps Applications, the blog contain several interesting tutorial, especially v3 API of Google Maps.