I gave a presentation on O/R mappers including Class::DBI at OSCON two years ago. I'll brush it off and make it an article.

Perl web application framewokrs: CGI::Applicaiton, Maypole, CGI::Prototype, etc.

I'm giving a presentation on this at YAPC::NA and OSCON this year. I'll make it an article after the conference.

UPDATE: Incidentally, the enterprise perl book is called Perl Medic.