Myths About the First Thanksgiving (Turkey, "Busiest Travel Day," Edward Winslow's Letter, Pilgrims, Wampanoag/Ramona Peters, etc.)
MTV's "Decoded" Series is fabulous, in general, and their "What Thanksgiving Got Wrong" hits many the key points in an easily accessible (humorous) skit.
The "Real Story" has history of Presidential involvement; choosing the date and it's problems; sports games; parades and their balloons; and Plimoth Plantation.
The British connection give more information on the pilgrims and widens all perspectives.
http://mayflowerhistory.com/tisquantum/ and http://www.biography.com/people/squanto-9491327
What did they really eat?
Telling Thanksgiving's Story in a Vanishing American Language
Common Native American Stereotypes Debunked
Native Americans are killed at Higher Rate than Any Race, and Nobody is Talking About It