Not too many troll responses to this topic which would normally be along the4 lines of JohnBinghamis gayandJeffGallowayisaPenguinputa fodder on this board. People will fear the long arm of the law...even here.
Start the greenhorns with just running in comfortable attire around a grass field or track for a half-hour with at least 3-5 minutes (or ideally 30 minutes without stopping) of sustained jogging and let them take a 60-second walking (not sitting down or total stopping) break as needed. Get them to that half-hour mark before you try improvising much in the way of other workouts. HAVE water on hand...it's not wimping out to need water when they are running and sweating, especially when out of shape.
Still, unless they are completely unfit, any reasonably able-bodied recruit with some determination should be able to grind out 5-miles to 10K minumum in distance within three weeks, just covering the distance for a 'long' run' once a week, not really into pace yet, just not stopping and getting them a 'base' so they are strong enough to withstand the effort of running harder for a sustained effort. And they should be able to handle running 5 days per wqeek (4 is OK on easy weeks but that's pushing the law of little return--the other during-the-week runs are shorter of course) or there is little real progression.
Implement shorter, quicker runs during the week ranging from 15-30 minutes (it's not worth putting on the shoes to run if you don't go out for 15 minutes, even if it's a slower beginner--put them on the Stairmaster instead). Take two days off during the seven in the week as needed.
Then you can start dialing in the pace a bit with 7-10 minutes EZ jogging to warm things up, 3-5-minutes pick-ups at goal or a slightly faster pace, with 60-90 seconds of very slow jogging x 3-4 sets, 7-10 minutes EZ jogging to warm down aka cool down. Punctuate the workout with 4-6 pretty snappy 100-meter strides (near-sprints but not necessarily all out) as you get closer to D-Day.
And if someone is quite overweight, they might have to drop some pounds on a stationary bike or stairmaster, elliptical trainer, etc., before they can handle the pounding of running which takes a much greater toll on heavy bodies.