Sag is how much the suspension settles under both it's own weight (free sag) and with the rider sitting in posistion ( total sag). I'll have detailed directions and pictures with a sag calculator on our web site soon. Typical range is:
Rear free sag 2-8mm
Rear total sag 25-32mm
Front free sag 22-27mm
Front total sag 35-42mm
Sag is only a starting point and should not be take as absolute values becuase tires, geometry, suspension settings, track or road conditions, and rider preference ultimatly will determain the settings. However if you find your setting radicaly different, I would suggest trying a different spring rate.