Who are the Neua? the Manao? the Lohra?
Searching for books about different people is similar to searching for books about far away places. You can look about in the 900s for geography and history or search in the catalog for the name of the group that interests you. For a fiction book go to the catalog and put in a place or group of people followed by - Fiction. For example Java (Indonesia) - Fiction or Inuit - Fiction. Not fun. Not easy. And you are unlikely to find many of the most interesting, often endangered peoples because you don't know their names.
The study of cultures is part of anthropology, specifically ethnography. But there is no Dewey place for anthropology. The archeological part is apt to go into the 900s somewhere. Linguistic anthropology into the 400s. Biological anthropology is scattered about in 573, 576, 599 and 611. And books about living cultures often get hidden in 305.8, buried under all the sociology and social psychology. Never mind that to an anthropologist the various subfields of anthropology are all connected, intertwined, they aren't in Deweyland.
Probably the easiest way to first find fascinating people you never knew existed is to go to the reference room to 305.8. Find these books and browse through them.
Endangered peoples of North America : struggles to survive and thrive
Gale encyclopedia of multicultural America 2 volumes
Las razas humanas 4 volumes, wonderful pictures
Countries and their cultures 4 volumes
The Encyclopedia of the peoples of the world
Encyclopedia of the world's minorities 3 volumes
Try it. Discover the Neua, Manao, and the Lohra. Read about the great warrior princess Nyennega, ancestress of the Mossi. Find out what happens during an Ifugao wedding ceremony. Answer these questions - What do Amahuaca boys learn? girls? Where do they sleep? What do they eat? What do they wear?
Start your own quest for more information on any group that fascinates you.
Another good way to begin? Read almost any issue of National Geographic Magazine. In the J room we even have National Geographic Kids.