Be advised: I was going to make a legitimate work out post with diagrams in mspaint, but I decided I'd rather play Deus Ex: Human Revolution. If you guys actually want that, I'll do it eventually. Just keep in mind this game is ******* amazing, though, so be patient.
Just to get you back into the game, I'd go with this for now:
Push ups
Sit ups
Squats
Pull ups
Running
Now, when it comes to do these kinds of exercises, people like to take the easy way out. I don't understand it, but it happens every time. Don't half ass the work out. Don't take 15 minute breaks between each exercise. Find out what your max number of reps is for each exercise. Once you've established that, you can either do pyramids (which I'll explain right after this), or you can try to go for your max every set. By the last set, you should be thoroughly ****ed up.
A pyramid is starting with a relatively low number of reps, increasing with each set until you hit the apex, or the middle set, and then work your way back down. You will most definitely see results this way. That said, I prefer aiming for my max every time. Why? Because working out is almost entirely mental, and I always feel like I have more to give after doing pyramids.
The way you should do the above exercises is do your max, rest 1 minute. Do another set. Rest 1 minute. Do this for 5 sets. It doesn't sound like a lot, but again, if you're doing the exercise correctly, you'll be thoroughly ****ed up. Especially with the squats. Once you've done that a couple of times, obviously taking rest days (which is when I usually run), you can mix it up a bit and rather than rest, do a different exercise. So you do your push ups, then do squats, then do push ups, then do squats. Until you're done with that. Then move on to the sit ups and pull ups. Obviously, do it in one day. There's no reason why the above should destroy you to the point where you're only doing 2 exercises a day. If you do less than 10 pull ups, you should probably do a pull up/push up mix.
Proper form is key with all exercises. When you do a pull up, you're not kipping or cycling like a mad man. You need to be able to do a dead-hang pull up. That's going up, chin above the bar, go down, arms locked out. All the way back up. Anything less is cheating yourself. You only get what you put into it. When doing push ups, chest hits the deck, go back up. You can do it fast like a mad man, or you can do it slowly and actually build strength. There are pros to both, but you're going to want to start off with actually building a base with which to work with. Start off at a slow speed. Watch videos for squats and sit ups. With squats, don't hurt yourself. They're just prison squats. Your ass doesn't have to hit the floor. But don't do retard squats, either, where you go down an inch and call it a day. There are a million kinds of sit ups. I'd go with the standard lie down on your back, legs raised forming a 90 degree angle, arms on your biceps and have your elbows touch your knees. Then do side sit ups or whatever they're called where you have one leg on the ground, one leg raised forming a 90 degree angle, and have your opposite elbow touch that knee while your other arm remains on the ground.
In any case, this is probably the most basic routine one can do. But its a good way to get back in the groove. If you feel too weak to work out the next day, go sprinting. I hate running long distance, so I do 800m sprints 4 times and call it a day. Do whatever you want so long as you're destroying your body temporarily. Don't push yourself so hard that you're causing long term damage, though. That's just stupid. Remember. Rest and nutrition is just as important as actually working out. If you overwork your body, you're not going to see any results. You'll just end up feeling weaker because you're all torn up.
