Your training routine should include exercise and rest days. On days when you train, you should be focusing on one or two parts of your body. Make sure you're spreading out the training evenly so you don't get too tired. Here's an example of a weekly training schedule:
Day 1: Chest, shoulders and triceps
Day 2: Rest
Day 3: Back, and Bicep
Day 4: Rest
Day 5: Legs and abs
Day 6: Rest
Day 7: Rest
Remember, rest days are important. They give your body time to build muscle.
This routine was found on bodybuilding.about.com and is for Beginners.
3 Days A Week Full Body Routine:
(Perform on 3 non-consecutive days such as Mon/Wed/Fri)
75 Degree Incline DB Bench Press
DB Bench Press
One Arm Rows
DB Pullovers
Bent Over Lateral Raises
DB Upright Rows
Dumbbell Curls
Overhead Triceps Extensions
Leg Extensions
DB Squats
DB Lunges (Press with heels)
Lying Leg Curls
Calf Raises
NOTE: DB = Dumbbell
How to Make Progress:
Perform 2 sets of each exercise for 10-12 reps and rest 1 minute in between sets. Move up to 3 sets after 4 weeks. At 2 sets per exercise the routine lasts 45 minutes if you rest 1 minute in between sets. At 3 sets it lasts 60 minutes. Do cardio on the days off (20-30 minutes) and also do abs (4 sets of leg raises and Swiss ball crunches for 15-40 reps).