Below are a warm-up (to begin with) and seven exercises to be done daily. This entire program should not take more than 15 minutes a day. These are all simple exercises that everyone has some knowledge of, and should be easy to do.
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Warming up
Any exercise program should start and end with a short warm-up. Rotate your arms in circles clockwise and anti clockwise about ten times each way, run on the spot for 30 seconds or so, pumping (swinging) your arms vigorously - increase the temperature of your body in this way, and up your heart rate.
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The Exercises:
Exercise 1) Pushups:
Also knows as press-ups.
Step 1: Lie chest-down on the floor with your hands slightly more than shoulder-width apart. The hands should be placed on each side of the chest, with the hands facing outwards. The feet can be either together, or about shoulder width apart - your toes and the ball of your foot touch the ground.
Look forward, not down at the floor - if any part of your face touches the floor, it should be the chin, rather than the nose. Now breathe in deeply.
Look at the image below:

Step 2: Now, push up off the floor by straightening your arms. Exhale as you do this. Keep the hands and feet fixed in position on the floor, and keep your back straight as you push up. Stop for a moment in this position. Look at the image below:

Step 3: Now lower your body down to the floor again by bending your arms. Breathe IN deeply as you do this. Keep your back straight as you do this.
Lower your body until your chest touches the floor. Keep your knees off the floor - your legs should make contact with the floor through the toes and the ball of the foot.
You have now returned to your position in Step 1 and have completed one pushup.
Number of times to do this exercise:
For already fit people who just want to maintain their fitness: 25 repetitions continuously.
For people trying to get in condition: 10 repetitions continuously.
For people who are out of training: 1 to 3 repetitions.
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Exercise 2) Sidebending: This exercise improves flexibility and works the muscles of the torso. Stand with the feet slightly apart and hold the hands above the head. Now bend the body sideways, from the waist, first to the left, then straighten up again, then bend to the right. Bend as far as you can without straining yourself too much. Look at the pictures below:

Count one bend each way as one repetition. Number of times to do this exercise:
For already fit people who just want to maintain their fitness: 20 repetitions continuously.
For people trying to get in condition: 10 repetitions continuously.
For people who are out of training: 5 repetitions.
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Exercise 3) Knee-bends or Half-squats: Stand with your feet shoulder-width apart and your feet flat on the floor. Then half-crouch down as if your were about to sit in a chair. Do not go all the way down, but just to the height shown in the pictures below..

After crouching, return to the standing position.
Inhale as you go down, and exhale as you rise.
Inhale as you go down, and exhale as you rise.
Number of times to do this exercise:
For already fit people who just want to maintain their fitness: 30 repetitions continuously.
For people trying to get in condition: 20 repetitions continuously.
For people who are out of training: 15 repetitions.
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Exercise 4) Dorsal Exercise: This exercise strengthens the back, abs and thighs. Lie face down with the hands clasped behind the back. Now raise the trunk and legs off the ground simultaneously. Hold this position for a second or two, then lower your trunk and legs to the floor.

Number of times to do this exercise:
For already fit people who just want to maintain their fitness: 20 repetitions.
For people trying to get in condition: 10 repetitions.
For people who are out of training: 5 repetitions.
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Exercise 5) Burpees:
Step 1: From standing, go down to the crouch position with your hands on the floor:

Step 2: Then (with the weight on your hands and arms) shoot your legs backwards to the position below.

Step 3: Now, again placing the weight on your hands and arms, return your legs to the crouch position, and then stand up. This is a 'burpee' - Count this as one repetition.

Number of times to do this exercise:
For already fit people who just want to maintain their fitness: 20 repetitions continuously.
For people trying to get in condition: 10 repetitions continuously.
For people who are out of training: 5 repetitions.
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Exercise 6) Sit-ups: Lie on your back, then rise without use of your arms, almost to a sitting position. Return to lying on the back. You might find this exercise easier to do if you get a friend or family member to hold your legs down as you do it. See the images below:

Number of times to do this exercise:
For already fit people who just want to maintain their fitness: 20 repetitions continuously.
For people trying to get in condition: 10 repetitions continuously.
For people who are out of training: Between 2 to 6 repetitions.
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Exercise 7) Spot Running: Run in one spot, raising your legs about six inches off the floor, and pumping (swinging) the arms. Count a left step and a right step as one repetition.

Number of times to do this exercise:
For already fit people who just want to maintain their fitness: 60 repetitions.
For people trying to get in condition: 50 repetitions.
For people who are out of training: 40 repetitions.
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That's it. This is not intended to be the 'ultimate fitness program' or anything of the sort. It is just a simple, useful set of exercises for people who don't have much time to exercise.
Fit people can use it to maintain their level of fitness; not so fit people and people out of training can use it to better their fitness levels. For example, if you're doing the number of repetitions for each exercise that place you in the 'out of training' category, try to increase the repetitions over time so that you move into the 'getting in condition' category, and finally, of course, into the 'fit' category.
Some useful advice: Vary the exercises you do - on some days, do the above routine, on other days, go for a run in the park - run 10 minutes, sprint two minutes, walk five minutes, repeat. Do this running/sprinting/walking routine at least twice, aim for four times. On other days go to the gym and do the heaviest weight exercises - the bench press, the shoulder press and the squats, with the heaviest weights that you can safely manage. At least three sets of ten for each exercise. Increase the weight over time.
On weekends, you could spend half a day or so hiking in nearby mountains (if any) or kayaking or playing some reasonably strenuous sport. Fitness can be fun. Treat your body well and the benefits will be considerable, in terms of health, mental alertness and the ability to smile in the face of fortune and misfortune, to take amicably the ups and downs of life.
I hope this will be of some help to someone out there. Take care, all.
My thanks to ellentemplar for some additions to this post. Also, below, some nice additional suggestions by Saint Micheal:
Crunches could be a good alternate to situps just double the normal repetition.
You can also do army presses. Instead of showing my sexy self doing them, all your really doing is standing up and then pushing your arms straight up in the air and then bring them down. In order to feel any burn you would normally want to do at least 100 a set.
Another good exercise is the bicycle kick, in which you lay on your back and then with your feet in the air move them like a bicycle.
Also another good for a good challenge, put you feet on a chair and then do push ups or sit ups, with this higher elevation it makes it a bit more changing since you have to go higher and lower then you normally do.
That is some army fitness stuff I remembered.
You can also do army presses. Instead of showing my sexy self doing them, all your really doing is standing up and then pushing your arms straight up in the air and then bring them down. In order to feel any burn you would normally want to do at least 100 a set.
Another good exercise is the bicycle kick, in which you lay on your back and then with your feet in the air move them like a bicycle.
Also another good for a good challenge, put you feet on a chair and then do push ups or sit ups, with this higher elevation it makes it a bit more changing since you have to go higher and lower then you normally do.
That is some army fitness stuff I remembered.
Saint Micheal's descriptions are pretty clear, if anyone needs additional help/images, etc. just ask.


