Resources: Chinese Minority Languages
Check out Ethnologue - http://www.ethnologue.com/country/CN/languages .

For specific information on each Chinese minority language click on "More information"

i.e. for Narua (6b (Threatened). Language of recognized nationality: Mongolian. Sichuan Province speakers assigned to the Mongolian nationality. Language of recognized nationality: Naxi. Yunnan Province speakers officially classified within Naxi nationality), it will lead you to:

http://www.ethnologue.com/language/nru

For learning, if you click on "Language Resources" you get:

http://www.language-archives.org/language/nru