Cool to hear that Doc! If you have any questions I’m more than happy to help. Also, though it’s not a very active forum over at HST we all try to be helpful.
Don’t get too caught up in some of the details of the 15s, 10s, 5s, which are just a way of organizing things. Some people who think the 15s are too easy but want to stick the general template do 12s, 8s, 3s instead.
I’ve dumped all of that and just shoot for a number of target reps generally between 40-60 per body part and get there however I think is best for that body part and amount of weight. I’ve really seen some great benefits from using techniques called M-Time (heavy timed singles), any Myo-reps (a lighter “pre-exhaust” style where all the follow on groups of reps after the first are done in a certain amount of time). Both are great for getting the maximum out of each rep, though you might want to stick with a more vanilla scheme first time through.
Since you’re trying HST I’m guess that building muscle is your priority. It also sounds like functional strength, like moving furniture is also important, as such I agree with and would suggest the following:http://www.bodybuilding.com/fun/hardgainer18.htm
I believe the following are the best basic free-weight movements: deadlift, squat, chin (supinated grip), press, dip, row (with a dumbbell), shrug and bench press. Beyond this are the best assistance movements: side bend, crunch sit-up, back extension and L-fly-these help protect the back and shoulders. The order these exercises are written in, in my opinion, is the order of their importance in building strength.