Pull the cotter pin out, camber is read off of the side 2 bubbles (one sides negative the other positive), make sure whatever tire you are checking is square with the rear end (use a wheel base gauge to do this) caster is off of the center vial. To check caster you turn the wheels to the outside 20 degrees and level the gauge on the hub, adjust the center vial to get 0. Now turn the wheel the other way 20 degrees from straight (20 degrees one way then 20 degrees the other) then that is your final caster reading
Dan