I doubt there is a *good* book on CGI Programming (especially large applications), as there probably isn't a *good* book on perl (well, uhm besides Camel & Llama), but I can recommend CGI Programming with Perl 2nd Ed, the first edition is completly online here... Oudated but also pretty educational is Web client programming with Perl, completly available online at mentioned URL.

Outside Links has a list of several good Perl (and other books)... You might wanna check that out.

Greetz
Beatnik
... Quidquid perl dictum sit, altum viditur.