Demaestro - 10:09 pm on Jul 5, 2010 (gmt 0)
Have you created a listing in Google Business Places?
If not that is the best place to start.
This will allow you to associate your website to a brick & mortar store. You can adjust the map placement and more.
If you have this setup already make sure the listing is active and try searching with a geo location as Hoople suggests.