All you need is Lat + Lng to add markers if you need to, you can then add a marker to the map using the following. (You don't need to geocode then)
Code:
var Latlng = new google.maps.LatLng(myLatitude, myLongitude);
var myOptions = {
zoom: 12,
center:Latlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("GoogleMapContainer"), myOptions);
map.setCenter(Latlng);
var myMarker = new google.maps.Marker({
position: Latlng,
map: map,
title: "Your Location"
});
var info = new google.maps.InfoWindow;
info.setContent("<strong>Some Content</strong><br />Some other Content");
info.open(map, myMarker);
So I would imagine you would need a web service or something to pull a list of Latlngs + Address info to populate more markers from your database.
This is how I do it for some of my sites, the user enters the location of some stores or whatever and some content and I pull it out and create the markers.