Wow, really? As much as I have enjoyed playing with React, the docs seem very, very sparse to me. I wish I had a better suggestion, but for me it was a lot of trying things in code and googling Stack Overflow answers -- you know, the usual. (And this was, like, a week ago, not 6 months ago or whatever.)
Beside the other links, I found a few react libs very useful. react-router [1] and material-ui [2].
The second one also has an example application that is a great boilerplate (if you like material ui and their work). I've been successfully using it in a couple of small apps [3, 4].