Balmaha is where the Highland Boundary fault meets the east side of Loch Lomond. Look on Google Earth, get a slanting viewpoint and you can see it marching north-east to Stonehaven. You can also see the chain of islands running to the SW across the Loch marking where it is.
If you want to know where somewhere is, the two best resources I know are Google Earth and streetmap.co.uk.