Geocodezip - Using the Google Maps API v3
Geocodezip has put together a great list of examples and tutorials for creating Google Maps with V3 of the Google Maps API (and V2).
The examples range from the very simple (for example adding coloured map markers to a map) to more complex examples (such as animated driving directions). The list includes a number of examples of ways to use driving directions, polygons, polylines and create custom information windows.
If you are interested in or involved in creating Google Maps mashups then this long list of Google Maps examples and tutorials will undoubtedly prove very useful.