Here is a good article from MacWorld which gives a detailed look-through of the Google Maps Plugin (2.1.1). The article helps you with the installation and use of the various features for your Mac OSX Address Book..
Google instead of Quest
August 03, 2005 12:05 PM By Dan Frakes
Many users know that if you Control/right-click on a contact’s address in Address Book, one of the options in the resulting contextual menu is "Map of." Choosing this item opens your Web browser to a map of the address on MapQuest.com:
The thing is, many people—including me—prefer the steadily improving (but still in beta) Google Maps. That’s where Brian Toth’s free Google Maps Plugin 2.1.1 (4 mice) comes in—it lets you use Google Maps, instead.
I’ve heard more than a few “I wish Address Book would use Google instead of MapQuest” comments from readers and colleagues; Google Maps Plugin gives you that option and more.
(Read the entire article...)