So I have done a bunch of ngrx over the last two years running workshops, writing some Pluralsight courses and shipping projects.
Here are my top five picks, in this order, to learn or upskill on ngrx.
My Pluralsight Play by Play Angular and ngrx
This is a simple intro to ngrx and redux and how to use it with Angular.
Getting Started with Redux
This free course is by the creator of redux Dan Abramov. Although it's not in Angular and does not use ngrx it is a much watch background to the pattern that is redux.
The ngrx platform documentation
Now it is time to read the docs. There are lots of ways to do redux even with Angular so read the docs and do the demos, this will not take too long.
Official example application
The example app utilizes @ngrx libraries, showcasing common patterns and best practices. It is a deep dive that can take a day to wrap your head around if new to these patterns but shows a nice though implementation, with tests too. Try it on StackBlitz.
Two blogs from Victor Savkin
These two blogs are a great read to get a feel for naming and the benefits to using ngrx.
Using NgRx 4 to Manage State in Angular AUsing NgRx 4 to Manage State in Angular Applications https://blog.nrwl.io/using-ngrx-4-to-manage-state-in-angular-applications-64e7a1f84b7b
NgRx: Patterns and Techniques https://blog.nrwl.io/ngrx-patterns-and-techniques-f46126e2b1e5
Comprehensive Introduction to @ngrx/store
I love this article even if it is a little old now for going into detail about how ngrx and observables work. Some of the middle-wear discussion is a little dated but the concepts, explanations for the pattern and the awesome demo are why I suggest this article.
Well, I ended up with 6 but hey they are all too good!