JHR, if you are bringing somthing to the game you deserve more than normal/average which sounds like what you are getting. You sould like a good worker and smart guy, I can't get any of my guys to learn on their own, and the fact that you are here learning new things, and expanding your knowledge of the industry says a lot about you as a person and a professional. I am also close with my guys -we eat/drink together off the job. You should be able to have business conversations apart from your friendship.
I'd just explain to your boss that you feel like you add a lot of value to his business and you want to get paid more money. I'd explain how you enjoy working for him, and that you don't want to go to another company, but you do need to make more money, and if that is just not possible with him that you will have to take a closer look at your options with other businesses. Knee jerk reaction from a boss is to say no -you are getting paid fairly, don't like it tough luck. I'd have the conversation with him, and tell him that you'd like him to think about it over a weekend or somthing, and have a follow up conversation with him later. You don't want to put him in a position where he thinks he needs to respond to you without fulling thinking it over.
Good luck!
Greg