Perl is a rich language with lots of features, but you can get by fairly easily without all of the extras.
to get apache going with perl, search around for mod_perl tutorial or something along those lines. That will get you up and running with a perl cgi interface. The perl routines will extract the arguments from the web page for you, you just have to act on them.
Using the backtics, you can execute command line programs directly from perl:
my $name="crust";
`echo $name`;
Perl is very good at making "intelligent shell scripts" though it can be used for whole programs, cgi, etc.
As for how I learned it? Well, pretty much just by using it -- they didnt teach it in either undergraduate or graduate school. If I got stuck, I would just search around the newsgroup archive until I found a viable solution. It saved a ton of time when I did my phd research -- I had all of my experiments, data collection, and the extraction automated.