Yu-Gi-Oh, Duel Masters, Oh My!

My 6yo son (who is just learning sight words in Kindergarten), is a MAJOR Yu-Gi-Oh fan. He has a pile of cards that he can't keep up with. His main partner in cards is a boy from down the street who DOES read. Now, most of what my son knows about the game he learned either from watching the cartoon or by playing the gameboy game. I used to play Magic: The Gathering, so I know how most of these games are supposed to work, but this one seems to elude me somehow. I tried holding on to the instructions that came with the starter deck, but it always disappears on me. So I haven't had the chance to read it. I don't care to watch more cartoons than I already do (Yugi doesn't come on during the day), and I don't have time to pick up a gameboy and learn that way.

The interesting thing is, when they start playing I usually stay somewhere else in the house (and occupy little sister). After a while I hear various yells, screams, and other loud exclamations (nothing bad as far as I can tell). Yet, when I go check on them, they're fine. I can only guess it's just the excitement of the game. I've been thinking of taking my son to a local shop that runs games/tournaments so that he can watch others play, but haven't made up my mind yet. He's already a major fanatic, do I really want to encourage it more than I have?