Ub, I guess my question is, if he doesn't gain any size, will you still be happy?
I guess to offer some practical advice, check out
http://www.stumptuous.com/cms/index.php
This is a page with lots of advice for weight lifting -- don't be put off that it's a page written by a woman. She's stronger than 99% of the men you'll see at the gym, and so is anyone that follows her advice. You don't want to follow those guys advice anyways -- unless you want to sustain some serious injuries. She knows what she's doing! I followed plans set out by her and saw significant gains.
The old idea that you should do lots of exercises, every day, and lots of reps and sets doesn't really work for everyone. What I find works best is going mondays, wednesdays, and fridays, and doing a full-body routine consisting of 6 exercises. I only do a warm up set and then a work set. As well, I don't spend time doing isolation exercises. Movements that use lots of muscles at once. Squats are important! Too many exercises won't help, it has to be the right exercises.
Then, just rest on your days off. Cardio will take away from his weight gain results. And don't forget to EAT LOTS! I don't find a need to go insane tracking my meals, but just make sure to get lots of meat, and avoid junk food.
Also important is not lifting too much, and making sure you use correct form. If I can do 12 repititions of a movement, I will add about 5% of the weight onto it. If I can't even do 8 repititions, I know I'm lifting too much. To get bigger, I found I had to keep adding more and more, but only in very small increments.
It's difficult to adhere to these rules when you see big, steroid-dripping behemoths in the gym completely breaking them. However, if you have an idea about proper form, you will laugh at how horrible they actually are. You'll see the four or five guys or girls lifting impressive weights with good form, but they are the minority.
Hell, everyone has their own advice that totally contradicts everyone elses. (I'm sure mine does.) But you really have to just try things and see if they work. Why not start off trying what is easy? It worked for me.