There aren't many links about that. I can get links about black/Indian relations, but generally not about native Africans and Indians. The civilized tribes adopted slavery, mostly simply imitating Europeans, but it has become an excuse for whites to continue oppression.
There are some sites:
I've posted this link before. The Webmaster is black, Cherokee, and Filipino. He features articles by many activists. An excellent links page.
An NCAI transcript about the whole black/Indian relationship.
Black Native American Association. Some of the links are a little iffy, though, going to a point that most historians - Afrocentric or otherwise - won't go.
Center for World Indigenous Studies. Distributes information on ALL indigenous peoples.
A lot of people here have Cherokee ancestry. These sites are of federally recognized Cherokee bands. There are numerous state bands, but a lot of them aren't recognized by the Cherokees themselves. (There's even a Cherokee group here in Cali. LOL)
Also, there's a circa 1970s National Geographic with a picture of an Apache fancydancer who, IMO, could pass for black.