Okey dokey first off I have got it working on a demo site which you can see here due to not adding billing information the map might not load but the marker will and so will the dynamically filled info window.
The preview of the back of house is here
Check out the CMS and the Custom Code in the CMS template to get how I got it all working. As for getting the latitude and longitude you want to use the way google does it so I manually search google maps for the location then from the URL i pull out the lat and lng.
The first lot of numbers is the lat then after the comma is the lng. Input those into your collection and you should be sweet to go. Google only uses 3 numbers after the decimal so that is all I used in my example so your lat and lng will be:
Hope all of that makes sence.