The usual nightcrawlers found outdoors are not suitable for vermicomposting because they prefer to dig deep burrows in large amounts of soil and require soil temperatures of around 50 degrees. Redworms are preferred for indoor composting. In the Denver area, you might ask about buying them at garden centers and nurseries. Some bait shops also carry them. Redworms come to the surface to feed and then drag the food down into their bedding.
Worms can eat their weight in organic matter each day.
A pound of redworms will process a pound of organic material daily. The box will yield some moisture so periodically drain the box to keep the worms from drowning. You can feed the worms kitchen scraps, such as apple peels and lettuce. Do not, however, feed them dairy or meat products because these foods attract flies and cause unwanted odors. Worm castings should be removed once a month.