The "secrets" on how to generate a training plan

Total Heart Rate Training by Joe Friel was a revelation to me on where training programs come from (I experienced something similar when I learned babies do not grow in lettuces. Did you know they are not air-dropped via storks either?). Anyway, it gives you all the keys you need to structure a training program using heart rate zones. It assumes you know your current lactate threshold; let me know if you're interested in finding out yours - there is a qualitative, free! way to approach it, or I can point you to someone who does it with a portable device. Also, if lactate threshold doesn't mean anything to you, let me know and I'll post info on that too. If you get into this even deeper, you might look for Run Workouts for Runners and Triathletes by Bobby McGee, a catalog of specific workouts with which to populate a training plan.