Another easy way to add custom data to a Google Map is to create a KML file with Google Earth or with a text editor and host the file on a web server. A KML file that has a known url can be opened in Google Maps by entering its url in the Google Maps search box. While easy to create and share, these simple Google Maps created with My Maps or by opening a hosted KML file are not as feature-rich as Google Earth.
Google also offers the Google Mapplets API. Mapplets are small applications that run within Google Maps rather than being hosted on a third-party web site.
Learning to Use the Google Maps API
To add panels, special controls, and customized views to Google Maps, the Google Maps API is needed. The easiest way to begin learning about this interface is to visit the Map Basis page, which offers a "Hello World" example, and look at the code for the map.
For a range of examples of maps created with the Google Maps API, see Google's Google Maps API Examples page.
If you are interested in creating maps with this API, you should also look at Google's official Google Map API Concepts page.
A good way to begin creating maps with the Google Maps API, after you have a key, is to copy the code for the The "Hello, World" of Google Maps example. Replace the key in the code for this example with your own key. Then you can experiment with changing the code. In actuality, you can edit the code and reload the map while it is on a local machine without the proper key. But you will need to your key in order for the map to function properly on a web server.
Try out other simple examples that include choices of map views and other simple features, and use the code in these examples as a guide for making changes to your copy of the Hello World map. The map will need to be reloaded each time a change is made. Once familiar with the methodology for making changes, consult the API reference and go through tutorials to learn more. Try improvising with the code from the tutorials to make your own changes.
Even experienced Google Maps API programmers rarely start from scratch when initiating a project. Look for examples on the web for ideas.
Google Maps Mania is a blog that provides information about many examples of Google Maps that have been created using the API.
The Mapping Hacks web site also offers examples of maps that use the API on their Examples page.
The book Google Maps Hacks provides an introduction to the Google Maps API and gives dozens of examples. The book was written in 2006, and is somewhat out of date because it is based on version 1 of the Google Maps API.
The Marine Ecology at University of Washington, Tacoma - Sites Visited page is an example of a Google Map that offers links to species lists, other data, and slide shows for places visited by Dr. Bonnie J. Becker's Marine Ecology class.
NASA has created a Google Moon API Example.
Map of Repopulation Indicators for New Orleans (http://www.gnocdc.org/RecoveryByNeighborhood/index.html).
There is an official Google Maps API Blog.
The Google Lat Long Blog consists of news and notes by the Google Earth and Maps team.
Also see the Google Geo Developers Blog.
The Google Maps API Demo Gallery has examples of features implemented with the Google Maps API.
Google Maps Mania is an unofficial blog about web sites, mashups, and tools. Using the Google Maps API contains a list of links to examples developed with the Google Maps API and documentation.