I think the most important thing to do first is set your PRELOADS the same for the rear, and then for the front (the front will not be the same as the rear, but both rears will be the same and both fronts will be the same).
First off, don't worry about the acctual ride height, because you may need to add some weights to get the left/right balance correct. If you set your ride height before placing on the scales, the weight may show differently.
I did alot of work with scales on my old TC3. When I was done, the ride height was really weird. It was close to where I wanted it, but not perfect. However, the weight on each wheel was nearly perfect. The car worked beutifully for the first time ever. Then the Xray FK04 came out.
Good by TC3
Other may have their own way of using the scales. I though my method worked pretty darn good. I probably ended up in the same place as I would of using a different method. All I know is balancing that car made such a difference, it was night and day.