Not books but it's really important, in my opinion, to go through official documentation

https://learn.microsoft.com/en-us/dotnet/core/whats-new/

https://learn.microsoft.com/en-us/dotnet/csharp/whats-new/

Can also recommend reading:

https://learn.microsoft.com/en-us/dotnet/core/tools/ (CLI, it's good)

https://learn.microsoft.com/en-us/aspnet/core/fundamentals/m...

https://typescript-is-like-csharp.chrlschn.dev/pages/interme...

> are there books specifically about using .NET Core on Linux

There is nothing particular to using ".NET on Linux" - it just works. Standard Linux caveats not specific to .NET apply.