I use overlays but the best way for you to learn how would be to read the tutorial on the Google Earth site. I am a kind of "if everything else fails, read the directions type" so I wasted allot of time trying to jack with it myself first.
Hi Bronc88, I read a post about this (overlays in GE) a week or so back. I think it was on this site in the Civil War forum. It had step by step directions with screen shots. You may want to have a look there. Interesting and useful stuff for sure.