...and a lot of it depends on what you're doing with the car. Generally the sh!thouse roads require softer settings than a smooth track.There's lots of info on here about setting up the suspension, just spend some time doing a few searches.
that's pretty hard, I have mine set at just 5 for normal fast roadMines are at 15 clicks, and height is 335mm front 350mm rear (center to arch). No rubbing and handle well to my liking.