I'm not going to describe how to convert your location into geofield co-ordinates, merely how to render them out on a Google map.
Lets say you've used the Address Field module in conjunction with the Geofield module to create your locations geo-coordinates. These will be in a format of latitude & longitude which will look like: 54.592418, -0.1520028
See the link at the bottom of this post in the 'Related links' area for more detail:
You could always change the above code to use a precise location marker, different zoom parameters and that sort of thing. In order to embed the map all you need to do is insert this bit of html where you want it to appear: