Title: Mastering Perl/Tk
 Subtitle: Graphical User Interfaces in Perl
 Authors: [Nancy Walsh]
        [Stephen Lidie]
 Publisher: [O'Reilly]
 Publication date: 2002
 ISBN: 1565927168
 Pages: 766
 Price: 44.95 US
 WWW book information:  http://www.oreilly.com/catalog/mastperltk/ 
 Book's examples:  http://examples.oreilly.com/mastperltk/  
 Errata:  http://www.oreilly.com/catalog/mastperltk/errata/

This book, nominally on [Perl/Tk], is good enough and deep enough that I've heard even [Tkinter]
practitioners mention it as a help!