Dude for a beginner you are really overthinking shit, no offense I know you want to do everything right but, for the most part just get in there and train hard but EAT even harder.

Heres what I would do if I were you

1-Restart the SS program, keep your weights under your current PRs by 20-25 pounds to start off with.Keep adding anywhere up to 5 lbs per workout on squats benches and deadlifts,less for press etc.Focus on form and getting the required reps, rest as long as you need to between sets it doesnt matter too much, push this progression as long as you can, you should be able to push past previous PRs quite easliy if you eat well.

2- EAT, EAT and then EAT some more.Minimum of 1.5 grams of protein per lb of bodyweight 2 if you can eat it.And heaps of carbs.Try to get alot of carbs and protein for breakfast and then after you workout too.Watch you weight closely, weigh yourself weekly and at the same time of day (in the morning before breakfast is best IMO)If you putting on too much fat lower the calories slightly, if your not gaining eat more ,simple.If you find it hard to eat this much drink full cream milk or skim milk with your meals,it is simply awesome stuff and has everything you need to feed those hungry muscles.

3-Do a little low intensity cardio 2-3 times per week, just to keep the heart healthy and conditioning up to scratch.

Thats about it I dont know if this helps just my .02c