I've used carb or brake cleaner first, to get rid of any oil/chunks/crud.
Then I wipe down a couple times with rubbing alcohol and microfiber cloths (still see some discoloring, like the carb/brake cleaner didn't quite get everything).
Then I paint.
The latex gloves thing is good. It keeps the oils/salts from your skin/fingers from getting on the surfaces prior to painting and could result in adhesion problems at some point.
I would recommend trying some different patterns on cardboard or something first, till you get an idea for what colors/patterns you want.