Well there are a number of things you can do to both thicken up the chest and widen out the shoulders. On the shoulders, start doing shoulder presses, preferably standard barbell ones. That and cleans and upright rows should be the meat of your delt workout. My old weight training teacher got me onto presses and they really helped pack on the muscle there. Side lateral DB raises that hits the side head of the deltoid, which should really help widen you out. But also don't forget to hit the rear delts so that if you turn to the side your delts still look big. Plus the functionality of the joint will work correctly. Here is a sample workout that I'd give a try. Please be sure at least on set 3 or 4 or both you hit failure. I usually rest about 90sec on the first moves and then tighten it up to the usual minute rests.
BB Shoulder Presses: 4 sets of 6-10 reps
Smith Press: 4 sets of 6-10 reps
Upright Rows: 4 sets of 8-12 reps
Reverse Pec Dec/Butterfly: 3 sets of 10-12 reps
Side DB Lateral Raises: 7 sets of 15 with 30s rests (should swell the muscles up well)
On chest width, start doing pullups or chins. If you can't do your bodyweight yet, you can use an assisted pullup machine. Then once you can start doing your bodyweight, get a dip belt to start adding weight. Chins/pullups will widen out your back like none other. Also include back widening exercises such as wide-grip pulldowns, wide-grip seated cable rows. And be sure to throw in back thickening exercises like BB Rows. And work on thickening up the pecs with incline, flat and decline benches.
The key thing with any muscle growth workout is to maximize hypertrophy or the increase in the cross-sectional area of a muscle. Hypertrophy is the body's response to a high volume of stress. Volume is an expression of the greatest amount of weight lifted, for the greatest amount of reps and sets. So typically the rep range falls in the 6-12 range with at least 3-4 sets and 3-4 exercises per bodypart.
Be sure also to get your diet in order. You need to eat big and properly in order to see any gain in mass. Try taking a look at what you are eating for a week. Write down amount of calories, carbs, protein and fat. You should take at the least 1g of protein per pound of bodyweight. Then try adding calories to your diet and see what happens. Adjust as necessary.
Hope this helps and your shoulders are 3ft wide before you know it. Let me know if you have any further questions.