google map

Hello guys,
I’m looking for help on Google map, i’m using Directory press and like to know how can i set it up so that when someone clicks on a listing it also opens a Google map of the listing in edition to the other business info (based on the listings address, or postal code).
i have Google API setup but don’t know what else i have to do to have the map feature?
any help would be greatly appreciated.
Thanks
Jalal