Just found this thread via the 'dog bit toddler' thread yesterday. Wat a great idea to put resources in one place.
I have this video to add. A clear demonstration of dog body language when interacting with humans (very informative - promise no disturbing scenes).
It is fab one to show kids. My young nieces and nephews have all watched it with me, have tried it out on my dog and taken great pride when they find they can read the communication signals correctly.
The woman has a very, ummm, distinctive voice but what she says is spot on :)