Continuing the discussion from Welcome to the SketchUp Community!:
The easiest way for your son to place a SketchUp model in Google Earth is to use the “Preview in Google Earth” command in the File menu. You can read all about the process (there’s a bit more to it than I’ve described) in our Help Center article “Placing a SketchUp model in Google Earth”
John
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(Whoops: link didn’t work… Lemme try that again: http://help.sketchup.com/en/article/36241)