On the back of the CD, the red and yellow jacks say left and right output, but where do they go? Are they for sound or picture? What's the jack labeled "mixing"? Do I need that? I'm totally lost on this one.
Red is Right sound, White is Left sound. But I'm not sure why yours is yellow. The video output you use is still the one on the Genesis.
Red and white are phono RCA connections and go to a hifi or other sound equipment with phono inputs for stereo sound. "Mixing" is probably for a 3.5mm jack, like on headphones.