This plan is designed to build the fitness, strength, and endurance of most recreational riders, readying them for the demands of a weeklong peloton ride. As the plan progresses, riders should plan of increasing both the volume and intensity of workouts. PAA is a 550+ mile ride that has tremendous physical and mental demands over the course of its seven days. The best way to rise to those demands is to do the workouts and keep building time in the saddle.
This plan assumes that most people have not been riding much and may just now be starting to get on the bike. If you've been training and/or are experienced, please use this as a guide but do what works best for you.
Whether you're training with heart rate, power meter, or simply basing it on perceived effort, you can use the scale here to guide your workouts in this plan: http://www.locomotiv.cc/blog/2015/12/9/training-zones