in reply to Learning CGI and mod_perl
Part of the challenge that you face is simply determining what it is that you want to learn (how to do). What is the business objective that you are trying to achieve, and what business obstacles must be overcome?
We have come a lon-n-n-n-n-g way (thankfully...) from the days when Perl scripts read a GET/POST message as their standard-input and PRINTed their replies. The original CGI module (itself a light-years advancement over all that came before it) has since been augmented and extended by an immense number of “application frameworks” of various degrees of focus and complexity, as the members of the Perl community labored to make the best possible use of both their laziness and their hubris. :-D They are all right there, waiting for you, in CPAN.
When you are reading a text of even slight age, you might well find yourself being pedantically taught how to do ... “a thing that has already been done,” and “oh by the way, done very well indeed.” In that case, you're just wasting your time (if not your personal curiosity) “learning how to do that thing” all over again. One does not prepare for a long road trip by learning how to refine gasoline.
CPAN, “that luscious repository of ten thousand tested software modules,” is always the place to start ... and to finish. DRYOAE = Don't Repeat Yourself Or Anyone Else. Find the highest-level framework, or other body of existing, tested code, that you can find. Base your project on that.