Flux still have you a little flustered? Check out this article by Tyler McGinnis. In the third part of a six part series on React.js, Tyler breaks down Flux in a very composable manner. If you're new to Flux, start here.
In this article, Chen walks through the pitfalls he encountered when he dove into React. Stores are not models, don't overuse setState, and keep it simple, among a few other things.
If you're still using React.createClass to create your React components, check out this blog post by Kris Jordan. In this post Kris walks through everything you need to know in order to convert your components over to ES6 classes.
Interested in building an Isomorphic app with React.js? Check out this tutorial by Jonas Ohlsson. In this post Jonas walks through what he learned building an Isomorphic React app at work.
In this blog post Dan walks through how he divides his React Components into two categories, smart and dumb components. Doing this yields many benefits, separation of concerns, reusability, and more. Check out this article if you'd like a new approach to reasoning about your React components.