From the University of Washington Libraries, American Indians of the Pacific Northwest contains photographs and scholarly resources about the Northwest Coast and Plateau tribes, including the Tlingit and Nez Perce.
The Bancroft Library at UC Berkley has put together an online exhibition showcasing some of their rare books and ephemera related to Native Americans. View paintings and advertisements that reflect how Europeans viewed Native Americans as well as plenty of scholarship to accompany the images.
Finally, Surrounded by Beauty, from ArtsConnected, takes you through Native American culture and history by region. Check out the Northeast Woodlands to learn more about the tribes that used to live in the Philadelphia area. This is a well-researched website with beautiful images.
To see what the University Libraries has to offer on Native Americans, search the catalog by subject for Indians of North America. You can also search for specific tribes such as Eskimos or Alogonquian Indians.