There's a good (and extensive) tutorial on C# threads/threading by Albahari that many have found useful: [
^]
I bookmarked this answer to a CP QA question by Sander Rossell from 2012 [
^]; it is a useful collection of links to major articles on C# threading from a variety of sources, including links to information the Task Parallel Library, Reactive Extensions, and other newer features on .NET.
In 2014, one of my favorite .NET gurus, Eric Lippert, wrote what I think is a great "wake-up" call that challenges ideas many programmers have about threads in .NET. I suggest you study it: [
^].