Plimoth.org is the website of Plimoth Plantation in Plymouth, Massachusetts.
http://www.plimoth.org/kids/
It is a centuries-old Wampanoag homesite and attractions include a full-scale replica of the Mayflower and a 1627 English village reproduction. The section of the website I have linked to is especially designed for kids with fun activities like downloadable coloring pages and neat recipes for kids to try (with an adult). It includes stories about 17th-century life and what it was like to be a Pilgrim or Native child in the 1600s. There are also games and things to do that kids today can still make and enjoy. And if you have a homework assignment that has to do with Native or Colonial history, the Homework Help section has "enough stuff to fill up a whole bunch of reports."
For a virtual tour of the first Thanksgiving, visit Investigating the First Thanksgiving and the accompanying teacher's guide.