Derek Baird shared a link to a Yahoo Teachers document giving a simple guide to Del.icio.us Social Bookmarking for teachers, including screenshots. It’s short and understandable.
Of course, Del.icio.us is supposed to be coming out with a new version soon, so I don’t know how long this guide will be valid. But I suspect it will be accurate for quite awhile.
I’ve placed the link on my Teacher’s Page under Social Bookmarking.