For some reason it is quite hard to find a lot of quality resources related to reactive programming. There are a lot of those - they are just hard to find. So here's the list I find most valuable to kick off with reactive programming.

Note: Some of the links are js related and some are c# related but they are explaining core concepts of the rx.

1. Short article explaining the basic of reactive programming (js) The introduction to Reactive Programming you've been missing

2. For some reason the documentation for reactivex is not quite visible. This is probably the best place to learn the core components available in all language implementations. Subjects

3. Best online book with jsbin samples and detailed documentation on api (js, but as I said the api is simular for all languages) Introduction to RxJS

4. Decision tree that will help you get used with the api (have simular in the online book Introduction to RxJS Decision Tree

5. Interactive marble diagrams - really helpful to visualize what will happen with your observables when applying different functions Rx Marble Digrams

6. One of the good presentation with a lot of sample coding Matthew Podwysocki - Streaming and event-based programming using FRP and RxJS (FutureJS 2014)

7. RX explained by one of the people behind the idea - explained with pseudo language and math operations and logics Expert to Expert: Brian Beckman and Erik Meijer - Inside the .NET Reactive Framework (Rx)

8. How Neflix use it everywhere (js) https://www.youtube.com/watch?v=XRYN2xt11Ek

9. Really nice explanaition with examples from MSDN (c#) Using RX

10. 101 RX samples (js) 101 RX samples

11. Video examples (js) Video examples from reactiveX

12. Learn RXJS online book (js) Learn RXJS

This list will be updated over time.

Note: There are quite a lot of other resources out there - like MS introduction videos and workshops but there are quite outdated(2011 - 2012). And there is a upcoming book Rx.NET in Action that should be released this december.