During a literature search, ethnographies as well as collections of stories, myths, legends and songs will be instrumental to the researcher for information on societies, clans, keepers of knowledge, ceremonies, uses, processes and interactions. If available, dictionaries are a great source of information as well.
Nowadays, you may also find documentaries and oral interview transcripts or tapes.
Look for sources written or produced by community members and ask community members for recommendations. They often appreciate the question and will refer you to those sources they believe most accurately reflect their communities and were accomplished with integrity.