there are really so damn many ways to squat, even to squat with 5 sets of 5, or 6 sets of 4, or 4 sets of 6, or any similar thing, that there is not really any one program... im always hesitant to even write it out as a "program" becasue i dont really know what we will be doing in 4 weeks when we start such a thing... it kind of adapts as it goes.
but there seems to be some confusion as to the pyramid version or the non-pyramid version, so ill try to briefly explain the differences.
the EASIEST method we use for squats, and the one which rip used for beginners, is a simple pyramid program, the weights are pyramided BOTH monday and friday... and another leg exercise is used for wednesday, usually front squats for the young and athletically minded, sometimes leg press for the old and feeble.
say a person tests at 200lbs for 5 reps on their initial workout. well then monday they might do the following sets for 5 reps, 95, 125, 155, 185, 205. fairly equal jumps, ending with a 5lb personal record. if the last set is successfull, then on friday they will go for 210 on their last set, with adjustments on the other sets to keep the jumps about even as needed.
the average beginner can stay on this exact simple program for anywhere from 4 weeks to 4 months, as long as they continue to improve at least 5lbs a week, most can do this for quite a while.
when they stop improving, the first thing he does is to drop a couple of the "warmup" sets down to one or two reps, to decrease fatigue and allow a few more personal records on the top set... so that 200lb top set of 5 workout at this point would at this point have the 155lb set at maybe 3 reps, and the 185lb set at one or two reps, then try for 5 at 205.
this change usually lets people get new personal records for another 2-3 weeks, sometimes more.
at some point, of course, this doesnt work anymore. so now we change the monday workout to 5 sets of 5, still with heavy front squats or for some lighter back squats on wednesday, and the same pyramid on friday, trying for one top set of 5. the 5 sets on monday with the same weiight will be some amount less than the current personal record for one set of 5.
usually with this raise in volume, the weights are set somewhat lighter than they were, and people are given a few weeks to work back to their personal records, then try to go past them, invariably they will pass them, and invariably eventually they will stall again...
at this point we usually lower the volume of training, raise the intensity, in some form we will go with lower reps, lower amounts of sets, cut out a day of squatting, something to allow a raising of the numbers... again, the numbers will raise for a while, then stall again.
a this point, another raise in volume is needed, and at this point we will go to the program that most usually associate with the "5 by 5"... squatting 5 sets of 5 with the same weight 3 times a week, lighter on wednesday and heavier on mon and fri. you are all familiar with this i think, we raise the volume for 2-4 weeks, then slowly cut the volume aned intensity of most workouts, going for a big workout every 1-2 weeks, might be a single, a single set of 5, or even one big 5 sets of 5 workout. with people cycling down for a big contest at thsi point we might go for lower reps and try for the big singles.... with someone not at a place where a big peak is needed, its just cycling down to less sets but keeping the reps at 5, and trying to make a pr on a set of 5. this can be repeated several times over and over, but at some point you have to have a period of lower intensity training for a while in between cycles.
i will add that often, for the people with higher goals who want to really train hard, i will start right in with the 15 hard sets a week version, but with weights low enough that they can endure it, and when they get in condition and get used to the volume, will then go back and start at the normal place where rip starts right from the beginning. i find that people who have been athletically active, who have been training on other programs, etc, usually do well with an initial 4-8 weeks of high volume lower intensity training to get them mentally and physically used to this sort of training, get their form changed to a good squat, etc.
this post describes as much as a year of training for most people, with some that adapt well it is stretched to two years.... two years from when they start their initial "pyramid" workouts, or their initial month or so of conditioning with 15 moderate sets a week to when they get through their first real cycle with heavy weights and 15 sets a week cycled down to a peak.
it seems simple. it is.