I didn't really find it necessary to study prior to receiving information from Piedmont. You'll have plenty of time during ground school to study as long as you have the discipline to study in your hotel room or with other classmates.
My best piece of advice is to distill the information down to what you think should be committed to memory and make flash cards or some other study aid. This is for things like the bolded limitations, memory items, and certain specific, actionable system characteristics (for example, what gets shut off when you pull the fire handle). Study that stuff until it's really easy, and get your broader systems knowledge from ground school class.
As far as prepping for the sims, know your flows and profiles so well you can do it in your sleep. Don't wait until the sims to figure it out. Chair fly the flows and profiles with a partner. Don't just practice until you get it right, practice until you can't get it wrong. This will help you in the sims because you can focus on what's going on instead of trying to think your way through your flows and profiles.
Good luck. (But you should still avoid coming to Piedmont if at all possible.)