If you are new to working out in a gym, these workouts are a great place to start. Drill each one, once a week , for a total of 3 workouts a week. Give yourself 1 or 2 days rest inbetween each workout, so a spilt could be:
You will have to workout your strength levels to figure out what weight to use, keep you reps in the 15 - 20 range. This is know as the "endurance" range; and will give your body a safe, strong foundation to build upon.
Drill these workouts for 2 - 3 months and then you can move on to Body building or Strength and Conditioning training to further develop your body. Over the course of those 2 - 3 months you must make the weights slightly heavier each week as your muscles get stronger. Still make sure though you keep your sets in the 15 - 20 rep range.
Use a weight on each machine that allows you to fail with good form in the 15 - 20 rep range
Use a weight on each lift that allows you to fail with good form in the 15 - 20 rep range