• code written by people besides me (esp. at PerlMonks)
• perldoc -f {function} or just  perldoc perlfunc
• perldoc perlre
• perldoc perlunicode / Encode
• perldoc {Whatever::Module::ImUsing::JustNow}
• perldoc {some_pragma} (e.g. strict, utf8, open, ...)
• perl -d some_prog or  perl -e 'test code...'

The ranking is based (approximately) on correlates well with the number of times I've used each resource in the 12 years that I've been using Perl, and/or the total time spent with each resource. (Update: these are all sources that I still use often.)

I first started learning perl by working with a fairly large and elaborate (multi-source-file) app that was written in Perl 4 by someone else. I didn't really have time to read a whole book...

During that early introduction phase, I recall being astonished, first of all at the relatively low proportion of alphabetic characters in the code (the app was heavy on regexes and substitutions), and secondly at how quickly I was able to read it with comprehension and adapt it (partly because I already had the basics of regexes from using unix "grep/awk/sed").

The basics of syntax were never a problem for me, since it was close enough to C to be comfortable, and the sigils (back in the perl4 days, at least) were very easy to grasp -- having read their description once (I don't even remember which perldoc man page I read it from), it just stuck with me. I'm sure perldoc perlintro came in very handy in the early days, but by now I hardly remember looking at it.

(I'm not sure I would find it so easy if I were to start from scratch these days -- things have gotten more intricate and subtle, esp. with the sigils...)