I recommend four different workouts done on alternate days. Start with just three routines for the first six weeks. Once you have improved your general strength, add the shoulder routine as the forth workout. Starting the shoulder routine too soon creates a real risk of shoulder injury.
Using free weight you will have much faster results than the machines. However, the risk of injury with free weights is also much greater. Again, I recommend using the machines for the first six weeks, and then gradually phase in some free weights.
In general, start with a weight (or setting) that you can lift a minimum of 8 repetitions (reps). Gradually increase the reps as you are able. When you can do 2 sets of 12 reps, increase to the next weight level. Again, you must be able to do at least 8 reps at the new weight.
