The Google Earth blog carries this reefer to a fine set of tutorials for using, what else, Google Earth.

March 18, 2006
Tutorials for Google Earth

For an excellent collection of video tutorials on Google Earth I recommend this collection
created by Richard Treves. These are Quicktime files (podcast
compatable) videos with audio which show how to do basic things with
Google Earth including: “Flying with GE”, “Using Placemarks”, “GE
Tips”, “Overlays”, and more. Richard has a pleasant voice with a
british accent, and patiently explains each step, with clear visual
cues, on how to get more out of Google Earth. I'm adding this
collection to my Google Earth Basics collection. Richard seems to be adding to his collection each week, with plans for 10 so far.