All due respect, this is ancient in terms of how to build strength. I was doing 5x5 when I was 13 and it's a staple of powerlifters everywhere.
It's limitation is in central nervous system limitations otherwise I'd be squatting 2000 pds. This type of workout is all about motor neuron recruitment and adaptation. In other words, the more you do a single exercise, the squat, the better you get at it. First, more muscle fibers are recruited to lift heavy weight and more motor neurons are needed to get those muscles to contract but we can't continue to just add weight ad infinitum, there is both a mechanical and neurological limitation to this type of program.
If you want strength gains I'm all for a 5x5 as a starting point but in the links I read the sheer volume of traing is done at sub-optimal weights. IOW, you aren't really "adding" strength, until the point where the weight is heavy enough for you to engage more motor neurons, thus recruiting more muscle fiber, then add weight, to . . . engage more motor neurons thus recruiting more muscle fibers.
The downside to what I read was that you'd have to start with a totaly useless weight that you systematically increase without concern for recovery of the CNS.
If you want to do 5x5 I am always gonna cheer that one but don't squat and dead on the same day, that's dumb, squat, dead, then maybe stiff deads, or leg press on day 3, whichever you perceive needing more "lift" time.
Example:
Mon
Squat, overhead press, bent rows
wed
Deadlift, bench, and some skull crushers
Fri
any alternative leg exercise, I like the press
Do some heavy forearm work and I don't mean some 20lb dumbell burn, I mean stick 300 on the big bar, stand in front of it and just curl it with your fingers; hurts like hell.
Heavy bicep work
Don't buy into that 30minute bs. Start at 75% of one rep max, THEN, add weight ONCE a week, ONLY, on the bench, overhead, squat, deads and rows. Don't try to increase the weight every damn workout. From then on, add weight ONLY when you hit your reps.
If you want to really hit some numbers, cycle the reps down to 5x3 after 6 weeks, then 3x3 + 2x2. You finish 8-9 weeks and you WILL be stronger and be ready to cycle to a hypertrophy workout.
Now, if you are a new lifter, less than 3 years of lifting, hell follow his protocol to the letter. You'll get BETTER at the lifts, stronger, overall and have a very nice increase in fitness. When your joints start killing you, and they will, move on to a different workout protocol.
http://www.bodybuildingforyou.com/Images/exercises/forearms/wrist-curl-behind-back-1.jpg
Do forearm like that, NOT with the sissy weights, get in a power rack and load that bitch up.