To download
Google SketchUp, go to http://sketchup.google.com/. The Pro
version is expensive, but the basic version is free.
Warning: The download is slow. You will see icons on your
desk in parts before it completes.
In order to understand how to use SketchUp, the best option that I
found was the YouTube
videos on SketchUp for New Users. To explore a SketchUp, the
icons that you want to use are orbit, pan and zoom:
