Yes You Can

This is straight from Runner's World, May 2009

If you can walk continuously for 30 minutes, you can transition into a running program by gradually adding running to a couple walks per week. Start running at an easy pace, and stop as soon as you're breathing hard. Walk until you feel recovered. Then run again. If you can run only 10 seconds at at time, that's fine. (And if you can run comfortably for 10 minutes at at time, go for it.) As you get fitter, gradually run more and walk less. But as soon as you begin breathing hard, slow down. This plan consists of five workouts a week, to accumulate 150 minutes of moderate to vigorous exercise, as advised by leading medical groups.

1st month: Weeks 1 - 4 Three days per week: Walk 10 minutes. Run-walk 15 minutes, Walk 5 minutes. Two days per week: Walk for 30 minutes.

2nd month: Weeks 5 - 8 Three days per week: Walk 5 minutes, Run-walk 20 minutes, Walk 5 minutes. Two days per week: Walk for 30 minutes.

3rd month: Weeks 9 - 12 Three days per week: Walk 2 minutes, Run-walk 25 minutes. Walk 3 minutes. Two days per week: Walk for 30 minutes.