Worms need a place to call home - a plastic storage bin makes a nice wormy condo. Poke some air holes all over, and don't forget a top. The wiggly folk can, and do, escape.
Kids can tear newspaper into strips and soak them in water for moist bedding. Then add a handful of sandy dirt and the worms. When it's all ready, you can add fruit and vegetable scraps, eggshells, coffee grounds, even paper. But meat is a no-no.
The box needs to stay moist, but you also don't want to drown your legless friends. Unless you live in the desert, the food scraps themselves will probably add enough liquid. Peek when you feed. More torn newspaper can soak up any swamp, or add a little water if the newspaper dries out.
Within a month, your discarded scraps will be rich, black worm castings (aka. "vermicompost"). You can use everything, worms and all, in containers for growing plants. If you want to keep using `em as a garbage disposal, recruit some kids who love touching worms. Put the crawlies in one pile, vermicompost in another, and start all over.
Worms on the Web:
Worm World sells worms and equipment
Vermico Worm supply
Yelm Worm Farm "By the pound or ton"
Other Resources: Worms Eat My Garbage by Mary Appelhof