Here is the abbreviated routine that Peary introduced in the "Rader Master Bodybuilding and Weight Gaining System" in the pre-roid, Golden Age. The core of the program is 3 exercises (plus pullovers):
1. breathing bench press 12 reps
2. breathing barbell rows 12 reps
3. breathing squats 20 reps (1st set only, other sets 10 reps),
superset with
4. breathing pullovers 20 reps (using no more than a 20 lb barbell)
The breathing bench press and rows follow the same principle as the breathing squats. You take 2 deep breaths before pushing the weight out (bench press) or pulling the weight up (rows). This really revs up the metabolism!
Although Peary put the reps at 12 for benches and rows, it would be best to use a rep range of 8-12. Use all the weight you can to barely complete 8 reps. Then work up to 12 reps (do not try to increase your reps on all exercises during the same session - focus on 1 or 2 exercises each session).
The number of sets depends on your status. If you are a true beginner, then do only 1 set per exercise for the first month. Take a week layoff every 4 weeks. Continue with 1 set until the gains slow down. Then after a week layoff, go to 2 sets. Repeat this process and work up to 3 sets.
If you are an intermediate trainer, then start with 2 sets (if you are just transitioning from being a beginner) and follow a similar process as above and work up to 4 sets. If you have been an intermediate for a while and want to use this program for mass building, then start with 4 sets and work up to 6 sets.
If you are an advanced trainer, then you know what to do!
Rest between sets: try 2 - 3 minutes (since you will strive to use heavy weights).
Workout Frequency: It depends on you. Do this routine no more than 3 times a week. But most will gain fine on just 2 days a week.
Remember to rest properly, eat properly (include whole eggs in your diet if you can), and be persistent! Don't do any cardio or follow any other sports activity while on this program. Get extra sleep!