There isn’t much info on Cocos2d-x but that’s enough to understand main ideas. The problem is the framework is old so some things rendered obsolete. You’ll have to constantly compare the articles and the real life implementation.

Official documentation:

• Guide.
• Code documentation
• Forum, There are some tutorials there but they are mostly obsolete now.
• Functional tests; the framework developers see it as a demonstration of how everything should be used. You may often get “check in the tests” answer on the forum.

Also there are some series of posts:

• rezghob.com — probably the most recent.
• Some articles at raywenderlich.com: basics, small game, a game with map
• tutorial videos made by Sonar Systems (also available here).
• Some other blogs: one, two, three, four, five, six, seven, eight, nine

Books and cources

Learning Cocos2D: A Hands-On Guide to Building iOS Games with Cocos2D, Box2D, and Chipmunk — nice book from 2012 року, now obsolete.

Cocos2d-X by Example Beginner’s Guide", also mostly obsolete

Building Android Games with Cocos2d-x — quite new (2015) book with good examples.

Cocos2d Cross-Platform Game Development Cookbook — also new one (2016), but it’s about Object-C.

Mastering Cocos2d Game Development — one more from 2015

Also there are some Udemy cources: “Cocos2d-x v3 C++ - Beginning Game Development” and “Flappy Bird Clone - The Complete Cocos2d-x C++ Game Course".