This has been one of the recommended readings for our workshop students for quite some time: https://reactweekend.eventbrite.com

We also recommend the following:

9 things every React beginner should know. Take it with a grain of salt, but it's a good intro to some common React best practices. https://camjackson.net/post/9-things-every-reactjs-beginner-...

ES6 Guide. A nice resource for anyone new to ES6. Only sections 1-5 recommended. https://mrzepinski.gitbooks.io/es6-guide/content/

Edit: add additional recommendations.