For the running, I'd suggest the kind of workout I did when I ran cross country and distance track. Train for "overdistance" to build your endurance (if you're test is 2 miles, run 3 to 5), train for speed by doing timed ladder sprints (200m x2, 400m x2, 600m x2, 800m x2, 600m x2, 400m x2, 200m x2) once you've built up your endurance. Definitely work on improving the quality of your stride as well, as it will make the running easier. Heel kicks, leg lifts, bird steps, make sure you keep your arms up but loose, etc. Dont pound and plod as you run, you'll just hurt yourself, your steps should be kinda quiet and fluid. Also, in the weight room run in place with weights in each hand to build your arm strength and rhythm (your arms control your stride and pace).
For strength training, I'm a big fan of free weights over machines, as it forces all of the little stabilizer muscles to work and get stronger as well. Use dumbbells over barbells to help alleviate the need of a spotter so you can work alone if you have to. As far as actual things to work, that should be pretty obvious but do a thorough evaluation of what, where, and how much you're lifting to make sure you're both hitting all the muscle groups and not over or under training any specific areas. Definitely make sure to work your midsection and back, as thats the core of your strength.
For diet, cut out all the unecessary sugar. In the last year, I've lost close to 30 pounds (250 down to 220-230)
just from not drinking regular soda or bottled teas. When you eat carbs, which you will NEED to fuel all that running and training, make sure they're whole grain types and not white flour (which is high in processed sugar, which is evil). Whole wheat pasta, bread, fresh potatoes, corn, etc. The other thing you'll need is protein. Eat steak, eat beef, eat pork, eat chicken, eat turkey, eat fish (especially fresh salmon and tuna). If it was once alive and made of meat, its your friend so long as its not too high in fat. Dont forget your fruits and veggies either, bananas are essential due to their high potassium, oranges (or juice), apples, pears, strawberries, grapes, salad (without a ton of dressing) and everything thing else in a mixed vegatable freezer bag. Dont overload on any one food group, try to stay balanced but I personally tend to stray towards the "steak and potatos" with a caesar salad. Try to stay away from junk foods, but dont totally deny yourself either. Dont eat a box of twinkies or a tub of cookie dough. Everything in moderation, including moderation. In other words, dont forget to cut loose every once in a while and hit that china buffet up for 5 plates, eat a whole pizza, etc.... just dont do it all the time. Have a "fat kid" day where you just eat whatever. The other side of things that you may not like... if you smoke, quit. If you drink heavily, cut back or stop altogether. A glass of wine or a few cans of light beer wont kill you, but a bottle/2 pitchers/etc will ransack your body of nutrients it needs to grow and get into shape (hence the hangover).
Hope some of this helps or isnt too far off from reality.
