oh, one more thing. if you're like me and have a hard time putting on weight, you might want to give creatine a try. read up on it first, but i've had great results.
creatine is a protein found in red meat, but most heavy lifters tend to limit their red meat intake. plus, to get the amt of creatine you take in during your first week supplementing you'd have to eat an entire cow per day. it's not dangerous, but you do need to drink extra water while on it to help your liver and kidneys process the extra creatine (you should do this regardless, but especially if you're supplementing with creatine, protein...or pretty much anything including vitamins). you'll put on size and weight IMMEDIATELY (no joke), but a lot of it is water weight which will go away when you stop taking the creatine. the creatine combines to form ATP in your muscles which will allow you to do more weight/reps than you normally would. the ATP absorbs tons of water which is why you put on so much weight in your first week. the water will make your muscles appear much bigger (hey, at least you'll look good, even if it's only water), plus it will help your muscles to heal faster after your workout.
wait until you're nice and steady with your training schedule before you start to see the best results, and then go for creatine monohydrate, unflavored, non-instantized (non-instantized means it doesn't dissolve so keep stirring while you're drinking. the instantized has been *extra* manipulated in a lab and you don't want that. same reason you should go for unflavored). i get the generic Pro Performance brand from GNC (a month's supply is about $10). mix one teaspoon creatine, and one teaspoon sugar in a glass of water (the sugar gets the creatine into your system quicker and you'll digest less of it). i cycle it (month on, 2 months off) just because i don't want to tax my liver any more than necessary.
like i said, read up on it. you'll feel more in control and you'll be confident that it is abolutely not even slightly dangerous (just make sure to drink, drink, drink...water that is).