I want to find out how much I should be doing for each exercise. Now someone told me To "Start light and go to 20 reps... Then pick up a heavier weight and go to 20 reps. Continue doing this until I get in the 10-12 rep range and that should be the weight that I start with for that exercise next workout." Does this sound right to anyone? Or is there any other ways to find out how much weight I should be lifting on each exercise?