Link: Tom’s Astronomy Blog » Blog Archive » Google Mercury

Some Useful Tips:

Turn off all the layers related to Earth in the lower left corner

Turn off the Atmosphere under the View menu at the top

Under Places in the upper left corner, make sure the Mercury Dataset and the Featured Data are both selected

Named craters and other features on Mercury are marked by a circular marker

Featured MESSENGER images are marked by a small picture of the spacecraft

Click on either named features or MESSENGER images for more information