hey Mini - thanks for commenting again!
The routine I'm doing has me doing the same lifts, 3 days a week, but with a heavy day, medium day (-10%), and light day (-20%)...I don't think I could do heavy squats every other day but my recovery is good and I feel like this routine is working well for me besides my shoulder issue which I'm not sure is related to the workouts as I've had a history of bursitis even before I started lifting.
What kind of routine would you recommend for a beginner who wants to build muscle primarily?
Well, what you have said could work and you seem to gauge that it is working well for you. I'd say a beginner could do well on a 4 day split, something like Mon/Tue/Thu/Fri. Nutrition would be paramount and the macros tailored for him/her to best encourage and support muscle growth.
I had someone ask me a few weeks back what I thought about the minimum requirement of protein required daily for building muscle. Well, the American RDA (I believe) is 0.4g/lbs, but this is based off studies with relatively sedentary individuals. Logic would dictate that the more active you are then the more protein is going to be required; on a base level the protein will simply be used to fascilitate muscular recovery, preventing muscle/bone loss and providing your body with what it needs to either maintain or build muscle, depending on your activity type and the intensity level.
For strength training athletes I would be looking at at least double that, so 1g/lb bodyweight and upwards. The reason I am suggesting one gram/lb bodyweight and upwards is that people that train with weights are definately going to working at least twice as hard as the sedentary person (bit of a no-brainer there), so 1g would really be just a starting point. As you increase the protein markedly past this point, there has to be some optimal point where muscle building can occur ~ the ideal combination of training stimuli and protein intake/utilisation in the body. I'd have to look at the data for this, but I would say it's impossible to set a definative number as everybody is different, both with their muscular response to training, diet and how well their digestive system is functioning. Then of course you have the different types of protein, the main two being animal and plant... there are a lot of variables to factor in.
For an experienced lifter I would probably start around the 1.5g/lb bodyweight mark and take it from there depending on their initial response to that amount, beginner you could probably get away with a little less than that as they should be more responsive to the training stimulus (initially at least)
Keep up the good work, and sorry for my long-winded reply haha.