Maybe show them a segment of Vegucated, it has some good info, but the footage is not overly graphic. I also like that it shows the information through the eyes of transitioning meat eaters. It's on Youtube now. The section 16:30-25:40 might suit your purpose? http://www.youtube.com/watch?v=P9IqSn9l6Sg
Some information in Dutch would be good too (like you said in the Dutch products thread), but there aren't (m)any good video's yet, as far as I know.
I think it's really cool that you're participating in this. Let us know how it went!