I have discovered that my YouTube videos (original announcement post) about how to construct a basic map in Google Earth have become corrupted. So I've updated the video tutorials off YouTube in higher quality, the new Google Earth file can be found on this page of my online tutorials. Note this is for GE 4 so the controls look a little different now, it should still be useful though.
I came across the problem as I started experimenting with the tour functionality to see if I could use it for the same teaching purpose. If you're interested, I found it too fiddly for this use (admittedly not its main purpose).