Gmap Module open info window(bubble) from external link Not even sure where to start. 

Would like to have a menu in the sidebar that when clicking on a link will open an info window (bubble) in the Google map.

Any ideas on a jumping off point?
You can create a function that opens an existing infoWindow:

function triggerPopup(marker) {
  // Get the map using getMap() which needs the maps ID
  var mapID = $('.gmap').attr('id');
  var map = Drupal.gmap.getMap(mapID);
  map = map.map;
  // Get the map's current markers
  var markers = map.markers;
  // Trigger the popup for the marker passed to triggerPopup()
  google.maps.event.trigger(markers[marker], 'click');
};


Then you can use this function with any external link:

$('.your-external-link').click( function(e) {
  e.preventDefault();
  triggerPopup(0);
});


This gives you the basic idea of how you can trigger the popups, you'd need to figure out a way to associate the sidebar links with the markers - this is completely dependent on how you have everything set up.