Lots of good comments already but one thing not really mentioned. Starting with CGI for your first deeper Perl project has serious dangers. You may already understand some of the issues from PHP but you really should read up on CGI security. I think I'd probably already written about 10 production CGIs at work before I wrote my first secure one. :(
I did a Google search against thepen for cgi security and came back with lots of reading. Also be warned that CGI adds a layer of abstraction that makes learning in general more difficult and debugging specifically almost impossible for the uninitiated.