The answer to your question has to do with your personal goals. Do you want to focus on strength or aesthetics? There is a difference, both in programming and in the approach to training.
Focus on Strength
Check out an Intro on Strength Training I did a while back. It provides some information what that entails. The quick info as applies to your question is:
- Focus on compound lifts such as squats, bench press, deadlift, and overhead press
- Lower reps per set improve the top weight you can lift
- Programs are full body training of varying weights.
Focus on Aesthetics
This would be your bodybuilders. The "ideal" body has your muscles in certain ratios to each other so that you achieve a balanced physique. There's a couple distinctions between building muscle for strength and looks:
- Focus on isolation exercises to build mass where you want it, and not where you don't
- Higher reps per set improve sarcoplasmic hypertrophy (size)
- Programs tend to be split routines focusing on one muscle group at a time
Jim Wendler's Twist
Wendler was once a power lifter, and has devised a program (5/3/1) that can really be tailored to your end goals. His program is designed for advanced lifters, meaning someone who can only make strength increases once a month. However, there are some underlying philosophies that can be very useful depending on your current set of goals:
- Every successful program should have a strength component, a hypertrophy component (size), and a conditioning component.
- You simply vary the proportions of each to address your current goals; similar to the way you balance work, family, and play.
- Training sessions should be limited to about an hour.
Focus your training on what you want to do. For me, I am concerned more with strength and conditioning, but I still need that hypertrophy component to help the support systems in my muscles to sustain the heavier lifts.