You will want to look into learning harmonization and more importantly, counterpoint. This has been the text used since Bach for counterpoint. Otherwise, you can start here: http://www.musictheory.net/lessons

Analysis is huge as well. So track down some video game music scores and figure out the chord changes, leading tones, and whatnot.

Chiptune is a weird subset since there are only a few voices (three on a NES) and no polyphony but almost everything will carry over. Feel free to ask questions if there are things I can better explain.

For shame, brown cheese is delicious.

David Bazan is pretty great.