Native Languages of the Americas. This extensive site lists, in alphabetical order, hundreds of Native American languages, gives a brief introduction to their linguistic classification, whether still spoken and so forth, and then gives links to available online resources.
"A'ananin" is the language of the Gros Ventre, who live in Montana, and today there are only a few elderly speakers of the language. Zuni is the language of one of the Pueblo peoples in the Southwest, and there are 6,000 or so speakers of Zuni in New Mexico.
You can find resources like the Native Languages site by searching Google, but you might also take a look at our library research guides, which generally have a section on useful websites.
(Pictured here is Gros Ventre member Vernelle Chase, who was named Minority Business Advocate of the Year in an article in Indian Country Today last year.)