For N. American indigenous cultures maybe start with An Indigenous People's History of the United States by Rosa Dunbar Ortiz. It's a rough overview but manageable. Masters of Empire is a good book about the Anishinaabe people of Great Lakes region and there was recently a book called Seeing Red by Michael John Witgen that looks like it would be a good follow up. The Northern Paiutes of the Malheur by Dan Wilson is a good intro to one of the Great Basin groups. Chinookan People of the Lower Columbia, edited by Robert Boyd is a good overview of one of the Columbia groups.