Bisjac, teach me the mighty power of cool map making please!
you take screenshots of the completed local maps you make in game. they should be exactly 500x500 pixels/gametiles
then put it/them together in photoshop, with or without a grid, with or without markers yoiu want drawn on.
and run the image in a google-maps map.
you remove and add new image of new map as you add map tiles onto your image.
if your no good with java script, then use tools like
http://www.maplib.net/