Get an API-key
To obtain an API-key, go to https://code.google.com/apis/console. Please see this page for a detailed instruction.
Show additional information in a marker popup
Modify or override the 'setMarker' method in the Block's controller. You can add other attributes such as 'address', 'phone_number', etc. and use these in the view.php. Best is to create a template directory and copy the view.php file. Then look for 'marker['infoPopup'] = ' and change it to your wishes.
You can change the icon based on a page's attribute by creating an if/else statement in the 'setMarker' function of the Block's controller. The default icon is 'home.png', but you can download more icons and put them in the 'images' directory.