Charles Petzold has been writing about programming for Windows-based operating systems for 24 years. A Microsoft MVP for Client Application Development and a Windows Pioneer Award winner, Petzold is author of the classic Programming Windows, currently in its sixth edition and one of the best-known programming books of all time; the widely acclaimed Code: The Hidden Language of Computer Hardware and Software; and more than a dozen other books.
A good beginner's book, but if you're looking for something meaty to help you understand the intricacies of Winforms programming in C#, look elsewhere.
Also annoying to see copyright notices for every line of code. Copyrighting "hello, world"? Really? Shouldn't that be in the public domain, Charles?