Well, there's:

• perldoc CGI and other materials provided with the module itself.
• Wiley's Official Guide to Programming with CGI.pm (written by CGI.pm author Lincoln Stein)
• O'Reilly's CGI Programming with Perl (the so-called Rat book).
• Lincoln Stein's online materials.
• Ovid's online CGI course, his local manifesto, and japhy's online course.
• As well as numerous nodes and examples here. Just look around using Search and Super Search. You'll find many worth looking at.

Not to mention many, many others...look around; they're not that hard to find.

--f