If you want to show an actual map, why not just make use of the Google Maps API?
If you have an image and want to use it as a site navigation interface, then I think this is more of an HTML/JavaScript issue?
To do that you need to make use of the <MAP> and <AREA> tags.
http://www.w3schools.com/tags/tag_map.asp
http://www.google.com/search?q=html+image+map
Google may have an API to do this as well.