I just went straight into the docs. I feel we should always take the first feel of anything from the official docs. I learned using thinking in react. I also found this which will help you get started with react. Apart from that, I google anything I dont understand clearly and try to learn it. Moreover I love courses on egghead.io they have awesome resources.

As I already knew couple of langauges so I just went to codecadmy.com and took the JS lessons. They will feel very basics in the start if you already know other language, but still I suggest that we take it. There are always some small differences.

You don't need to know JS in depth to do React, but it is always adviceable. This guy has some amazing videos to learn core js. Very helpful to learn, as the language is bit tricky.

I hope that helps! :)

Thanks for sharing it, Much appreciated.