I've built things with pthreads a few times, and also used threading in Java, Rust, Python, and Ruby. (Edit: C# and Perl too IIRC. :-) The best book I've read about using threading safely was the O'Reilly Java Threads book. It's been about 16 years, but I remember it being a great "teaching the concepts" book, taking you through lots of pitfalls and showing how many ways you can mess up. It taught me way more than just Java. Like oldgeezr I kind of roll my eyes at the "you must be this tall to use threading" stuff, but I think I largely owe to that book both my confidence and my wariness. I bet it is still worth reading today.