Good multithreading guides?

The Dr. Dobbs article "The Boost.Threads Library" is a short introduction to the subject, using one of the Boost C++ Libraries.

That's not a tutorial, but a good set of articles Effective Concurrency by Herb Sutter.

Take a look at Concurrent Programming on Windows by Joe Duffy. The book is relative new (November 2008) and covers theory and practice ranging topics from the Win32 API to .NET Framework 3.5.

_{(source: barnesandnoble.com)}