Since they deal with kinship, here are a few links to way too much information on kinship types and charts.

Kinship and Social Organization: an interactive tutorial - Produced by an old acquaintance of mine, Brian Schwimmer at the University of Manitoba, this is probably the best online resource for learning about kinship networks and types of families. It's basically the equivalent of an Introduction to kinship course.

Essential Information & explanations, latest texts & monographs on Family.

David's Relationship Chart - There's a downloadable program and a massive number of links.

Marc