OK, if you have google earth installed on your computer this is how I do it: First, scan or take a digital pic of the map you want to overlay, then load it onto the computer. zoom your GE map to the area of your overlay. click on "add" at the top left, then select "image overlay" from the drop down. it will open a dialog box, use the "browse" button to select the image on your computer that you want to overlay. Then you can change its transparency level. The green square around the image lets you move, rotate and re-size. Every time you re-size you need to re-check your placement.
one last tip, the resizing is NOT constrained to original dimensions. It's more like it lets you stretch and compress it up/down and left/right independent of each other.
