My workout for weight loss (for beginners)

First, thank you all for your comments! Regarding this:
@rKaiser: I will write about gainning weight also, stay tuned.
@Mekor:Yes, that's the idea, every sport has his cardiovascular activities, and this means weight loss yes or yes ;).
Now, the workout:
We are going to separate exercises by muscles. Big ones will have more workout but don't forgetting the others.
But as I told, we are beginners so our daily workout will be very light first month.
Remember always stretch muscles we are going to workout. (I will blog about stretching too):
 - First we start with some biking: about 20 minutes: This is the base, always do some cardiovascular activity before starting.
Now, we are going to do full body workout but, very very light. Remember this is the begining of a long-length goal, so don't worry on how many you lift.
Numbers will be : sets/reps number of week (from 1 to 4):
[Keep the same weight 1st and 2nd week, the increase a little for 3rd and 4th week.]
[For beginners I prefer doing machine exercises but, if not posible, do it with dumbbells with instructor helping.]
-Chest: Bench press (Just the bar, or few weight!): 4/12(1), 4/15(2), 4/18(3), 4/20(4)
-Triceps pushdown: 4/12(1), 4/15(2), 4/18(3), 4/20(4)
-Shoulder press: 4/12(1), 4/15(2), 4/18(3), 4/20(4)
-Legs: Squat: 4/12(1), 4/15(2), 4/18(3), 4/20(4)
- Biceps: Curl: 4/12(1), 4/15(2), 4/18(3), 4/20(4)
-Back: Wide grip pulldowns: 4/12(1), 4/15(2), 4/18(3), 4/20(4)
-Calves: Standing Calf Raise: 4/12(1), 4/15(2), 4/18(3), 4/20(4)

After this we always do some normal abs: 4/15(1), 4/20(2&3), 4/25(4).
Done. Are you tired? Hold on. It's normal, but... - Treadmil for 15 minutes.

Well this is what I've done from Monday to Friday, but it is still good for a 3 days plan.
What's your opinion?
I will explain the proper way doing each exercise. I don't have many free time right now. Guess where I'm going now?