Should be pretty much self explantory. When you do your wiring for the joys and microswitches, you will use the NO terminal and the ground terminal. You can daisychain all your grounds and connect them to the ground terminal on the keywiz. I don't have a keywiz so I'm not sure how it is labled, but it should pretty much say joy1 left, button 1 and so forth and your coins will be like button 5 and 6 possible, you can drop RandyT a line or someone here can be more in depth that owns one. The wire you want to use is 22 gauge stranded and female quick disconnects, this makes life alot easier. I'm not sure on the optical route, not sure what you have there. Anyway, once you start doing it....very easy...
Tim