Twisted Network Programming Essentials
Abe Fettig
O'Reilly
I bought this book because I was having trouble making sense out of the Twisted on-line documentation.  I'm really a book guy, anyway, and felt I needed "The Book" for Twisted.  When the first page equivalent of "Hello World" blows up on Python 2.6 because of some obscure deprecation issue, you know you are in for real problems.  It gets worse from there.  I think this book was probably a great title years ago when the Twisted bits and Python bits were more in sync.  This book is seriously outdated and in need a huge revision.