We had a worm farm for about 5 months this past spring. The state extension service came out to one of our home schooling resource centers and did a preschool-age presentation to us and the kids about worms and how they decompose/eat scraps, how to care for them, the ideal worm box, etc. I'm sure your local extension service or state college would be into it if you could gather about 15-20 people including the kids. The student who came to our group said it was part of her credit-based study.
Anyway, the worm box worked out fine. We bought the worms, believe it or not, and by the time they got here in the mail they worms had made it almost totally out of their little paper bag enclosure. After 4-5 months, we did eventually move the worms into our container garden, where they have produced beautiful plants for us!
I would definitely do it again, but note that these worms don't do well in the worm box in cold climates. I think it has to be at least 40-50 degrees for them, so winters here are out. They did say you could keep the container in your basement but I'm not quite ready for that.
HTH!
Tara