Reference resources are a great place to begin your research as they give you background information on your topic. They can help you define terms as well as find overviews of topics, concepts and theories. They can also help you identify keywords or alternate terms for database searching. Many have helpful bibliographies that will point you to the key scholars in the field.
Companions and handbooks to a literature may contain one or more essays or chapters dealing with indigenous topics. Some may include individual entries for specific persons. See for example:
The Cambridge History of Canadian Literature
The Oxford handbook of Canadian Literature
The Cambridge Companion to Native American Literature
The Oxford Handbook of Indigenous American Literature