Originally, I kept them in a litterbox pan with a piece of poster board for a lid. I punched holes into the poster board for air circulation. I have since advanced to a plastic drawer system - which seems to be working well.
I feed them about a cup of feed once a week, place an apple or potato half in the drawers, along with a folded paper towel (for hiding and egg laying). Then I just wait and before long I have lot and lots of worms. Sometimes I have lots and lots of beetles - but that is good because they lay eggs and then I get worms.