So I wrote this out for Karl (unsolicitedly of course), and some of you guys might find parts of this helpful (but probably not), so I thought I'd put it up...
Here is the routine me and Kahn use - we don't do the legs part and just do cardio with legs instead. Couple of small variations - dumbbells for the shoulder presses, no smith machine, but yeah. It's all there basically.
Protein is the most important thing in building muscle, since that's what muscle is made of. ideally if you're trying to build strength, you want to get the number of grams of protein per day equal to 75% of your target weight in pounds. So, if you want to get up to 160 lbs, you want to get 120 grams of protein per day. this isn't always easy, so protein shakes are a great way to do it. It also is an easy way to eat something, so you don't have to worry about making/finding a healthy snack instead. The best reasonably priced protein powders out there are whey protein isolates, so called because they don't have any lactose or other fats, making it healthier and easier to digest.
I use VP2 from AST - they don't have it at GNC, but you can order it online from this site pretty easily. It's a good place to order pretty much anything - protein, supplements, gloves, water bottles, etc. it generally has the best prices for this kind of stuff, and it's the one I use. as far as flavors go, fruit punch and citrus blast are awesome, and you could add a little bit of juice if you don't like the flavor of the shakes on their own. the chocolate one is decent too, but the vanilla sucks. One that they do have at GNC is Isopure. Just makes sure it's VERY low fat and pretty low sugar. you don't need that crap if you're trying to gain lean muscle. Basically, I'd rather go for the Men's Health look rather than the World's Strongest Man look, so that's what I do - but that's what they're talking about when they say that what your goals are determine what you should be doing.
One thing people mess up is timing with protein. You basically want to have a shake (with one serving of the powder) 30 minutes before you work out, and then another one within 30 minutes of when you're done. It also helps to a have a little bit of carbs before and after a workout in those 30 minute zones, so i normally have a piece of fruit or a serving or so of leftover rice or pasta or a slice of bread when i have a protein shake. Some brands let you use milk or water, but milk is hard for your body to digest. so, just go with water. If you reeeeally like milk, you can do it for your post-workout shake, and make sure it's skim. I recommend getting some kind of shaker bottle to make these things easy to blend - I use an immersion blender, but there are a thousand different things. I'd get one that's powered and that you can drink directly out of.
As far as things beyond protein go, the only things really worth doing (and that's questionable) are multivitamins and creatine. For multivitamins, you only really need a basic one - you want something that at least has b vitamins, amino acids, and antioxidants. make sure it's time-release - otherwise you'll just pee it all out pretty immediately. also, when you take them, take them with breakfast. You have to take them with a meal otherwise they don't really do much for you. the ones I use are the GNC Mega Men Sport. Also good for nights of epic drinking. Yes, maybe multivitamins do nothing for you, but I really like having neon green pee.
So, creatine. It's a naturally occurring substance in the body and is available as a powder. it was mildly controversial ~ 5 years ago, but now widely accepted as being fine. it helps you recover from workouts, lift more weight, and get more reps in per workout. Here's a quick biased article on it - and one brand that i'd recommend. When you take creatine, just mix it into your protein shakes. On days when you're not working out, put some in a small glass of juice, ideally something non-acidic like grape juice. The sugars trigger an insulin response and help your muscles absorb more creatine. I'm actually cycling off the creatine while I'm down in South Africa - it's good to go off of it every now and then.
The biggest thing is just eating right. whole grains, fruit/vegetables, lean meat. For us carnivores, less red meat (<= 2x/wk), more fish(>=2x/wk). Develop a good standard meal that you can make and vary easily - mine is chicken sausage, frozen vegetables, brown rice / quinoa, all fried together in a pan using spray and not oil, with some spices involved. easy. I also try and do the 5 meals a day thing - keeps your metabolism going. So, breakfast at 8, snack at 10:30, lunch at 12:30, snack at 3ish, protein at 5ish (pre workout), protein at 7ish(post workout), dinner at 8, snack at 10 (as necessary). The 90 minutes or so after you workout is when your body is burning through calories, so that's a great time to eat big. seriously though, eating makes a bigger difference than anything else. If you go from 4,000 calories / day down to 2,500 calories / day, it makes a bigger difference than a 500 calorie workout. and there is no "I'll eat this huge slice of cake and then work it off" - things don't really cancel out like that, since your body burns calories from different sources for different things.
That's all I got for now. I can elaborate on any of this ad infinitum / nauseum if you ask...