Bill Starr is a genius. Buy his book: Starting Strength. Do his program for a year, then see if you want to make changes.
I train 4x a week, and have a Push Day (overhead press, bench, squat) and a Pull Day (Deadlift, Row, Powerclean, Etc) I do accessory work for smaller muscles groups on the day they fall so bicep and forearm on Pull Day, and triceps on Push Day.
Soreness will not be a factor as your only doing 25 reps for legs, not squats, then a bunch of faggorty like extentions and hamstring curls - both are useless for building strength.
Conditioning will be a factor. Your body will become accustomed to squatting 3x a week in 2-3 weeks. Just man up and do it.