Good topic to have - I'm a Man Of Large Size as well. This, actually, is my second time around with C25K. I was successful with it the first time, but I broke (shattered) my ankle and had to quit running. Unfortunately, my weight and bad fitness came back with a vengeance. After too much time out of it, I've started back.
Here's what I do know - don't worry if you aren't running. Seriously. This isn't a "running" plan as much as it is a movement plan. The only goal is to complete each days' program. If you can go everyday and work through that day, then do it. If you need to take a day between, do it. Do what you need to do to let your body work WITH you to complete each day.