warm-up really good either on a bike or running, then do some good ol' jumping jacks & jump roping to really get the muscles warm. After that spend about 10-15 minutes stretching.(It used to be thought that stretching cold muscles was a good thing, but it's really not any good for you.)
now it's hard to lay out a plan for you without knowing your condition and goals, but a basic outline would be something like this.
Push-Ups 5 sets of 25
Sit-ups 5 sets of 25
Pull-ups 3 sets of 4
Running: 6 miles in a week(best to pick 3 days and do 2 miles on those days)
once you get in better shape start getting more intense with your workouts.
Push-ups 20 sets of 20
Sit-ups 10 sets of 25
Pull-ups 4 sets of 10
dips 10 sets of 15
Running: Run 3 times in a week, at about a 7-minute per mile pace. Because the distances will be longer, split them up so you have time to recover. do something like.
Now aside from Calisthenics, use dumbells instead of barbell weights whenever possible. Barbells require both arms to push the same weight and your stronger arm will always help your weaker one, costing your weaker arm to be slower at gaining strength. Also Dumbells allow a greater range of motion to really get your shoulders, arms, etc in top shape. you can still do bench presses, military presses, etc everything you do with a barbell, but it's much more effective to use dumbells. 100lbs barbell won't you get you as ripped as 50-60lbs dumbells per arm!
Don't use hack-squat machines(standing squats at a slight angle) as they are useless, use leg presses(the ones where you lay down on your back and push up at a slight angle). also put your feet at bottom edges of them and just flick the weight up with your calves to get some monster calf workouts.
Of course diet is a big deal too, lots of fruits/veggies, and despite what these wacko "Tv Diet programs" say you're going to need carbs and LOT'S of em.
Supplements you DO NOT need however, If you're lacking iron, eat your meat a little more rare than usual as blood has high concentrations of iron. other sources of food contain iron(I.e Beans, whole weat breads, etc) as well, but nothing beats a medium-rare stake :) Synthetic minerals will never get you in good health, you've got to eat foods with the nutrients you need.
Just take it slow, and work your way up. If you can only run a 1/4 mile a day at the moment, that's fine, just slowy but surely start running an extra lap, than another, etc.
This program is more for building endurance(which you'll need), but use the weigh-lifting time(low reps & sets, but heavy weight) to build pure strength, you could also on somedays go with low-weight/high-reps to build muscle endurance while weight-lifting.
And don't forget...SLEEP, SLEEP, SLEEP! You won't get any better without proper sleep and most likely will be weaker after starting to train.
Find a high-rise that will allow you to use their stairs and climb as many flights as you can. This is a leg strength and cardio workout. Start slow and over time increase the number of stairs you do. As you get better, add weight using a weight vest or strong backpack. Add the weight slowly - over time. You don't need to run, a steady climb is what you are after.
Maybe the most physically challenging fire you will face is the high-rise fire. When that call comes in you will be expected to carry all the equipment you'll need (this may be as much as 70 pounds), and climb the stairs to reach the base of the fire. Then set up the attack and advance the charged lines into the heat and smoke. If you can handle this scenario, then you can do anything that comes your way.
In the Denver Fire Department a new recruit must successfully complete a 44 story stair climb, modeled after the above scenario; with an additional firefighter rescue thrown in. And it's timed! This is done at the end of the academy. The recruit's know about it from the beginning and train for it - five months. Still, because it is so physically demanding, some cannot complete it and are washed out. Check out the movie "A Firefighter's Journey". It documents this exercise in great detail. In fact, the guru of high-rise firefighting, Chief David McGrail, is the creator and instructor at this event.
If you don't have a high-rise to use. The stair machine is the next best. Don't think they are the same though. There is a big psychological factor that isn't present when doing the stair machine.