Okay, it looks like the choice is between the Plains Indians and the Iroquis. Depending on the final choice, here are my recommendations.
Plains Indians
First, are we dealing with Northern or Southern Plains Indians? I recommend the northern tribes, because of the greater familiarity. I also recommend concentrating on the Lakota Nation and her allies and enemies. For much the same reason.
Put the focus on the Lakota, with additional material on the Cheyenne, the Nakota, and such minor tribes as the Arapahoe and Crow. later works can expand into the Missouri River Valley, the Northern Rockies, the Southern Rockies, the Southern Plains. the Canadian Plains, and so on and so forth.
Iroquis
If the Iroquis are chosen instead we need to decide first on the historical period. Will we deal with the Iroquis of the Huron Wars, the Iroquis of the early colonial period, or the Iroquis of the American Revolution? In addition, what about the practice of torture among the Iroquis and the ritual cannibalism practiced by the Mohawk? How would that be handled?
Other Advice
Considering the size of North America I'd divide it thusly: Northern Plains, Southern Plains, Missouri River, Northern Mississippi, Southern Mississippi, Northern Rockies/Sierra Nevadas, Southern Rockies/Sierra Nevadas, The Great Basin. The North West, Northern California, Southern California, The Central Valley, Great Lakes, Eastern Woodlands, Gulf Coast, Florida, South Atlanic Coast, North Atlantic Coast, New England. Which should cover the U.S. pretty well. I will leave the task of dividing up Canada, Alaska, Mexico, and Central America to those better qualified.
One Last Thing
The
Open Directory Project and
The Yahoo Directory list Indian sites. Or you can do a
Google search on a tribal or national name. Have fun.