Personally I liked Kubernetes in Action from Manning. It actually explains the concepts and thoughts behind the various resource types and also has some chapters at the end which go into depth in how Kubernetes works under the hood.

Definitely helped in making me feel prepared for my day to day work with Kubernetes.

Yes, there are some parts out of date but nothing significant.

Some resources were only available in beta which are now regularly available, and some example definitions use deprecated features, but the CLI will warn you about the deprecations.

They have a second edition released in beta this year

Just checked and couldn’t find any PragProg books about it…