I'm not a pro trainer by any means, but been a jock my whole happily misspent life, so here's my free advice (remember what you're paying). First, get some books on training. There used to be some that were devoted to mx, but those are long out of print. What you want to do is develop two areas of your body: your aerobic capacity by running and your upper body strength by weight training. Joining a gym makes the second thing easier and will also put you in touch with people who can help you along. The running portion should be 3 to 4 times a week, starting out at a reasonable mileage (a few miles at first) and then increasing by 5 to 10 percent each week after that. Keep a log of all your training and do the weight work on your "off" running days and vice versa. Keeping a log will help you stay on track and keep you focused on the results. You'll notice a lot of improvement in the first two weeks or so, and then after a month or so the improvements will plateau. That's when the workouts will seem more like drudgery than anything else, but keep at it, becuz this is the normal way the body trains itself. Also, start to pay attention to what you eat and the amounts, and focus on improving your diet. Drink a lot of water, especially while training and don't overdo it or get discouraged. Training is a lifetime thing, not a quick fix.