Squats, Deadlifts, bench presses, dips, chins, rows, overhead presses. Those are the ones that pack on the beef. Add some arm work, biceps/triceps/forearms, calf raises, and sit-ups or crunches. 3 days a week will work for the average person. More than that will begin to use up the growth hormone that those lifts cause the body to produce and can affect it's ability to recover from the workout. Eat, eat, eat; especially protein, and get plenty of sleep.