Most of Perl is documented by the originators, better than most things I've had to wrangle.

Many of the books out there contain good stuff, but many more contain bad stuff. Trust is important, or experimenting or cross checking for verification.

You can "ask an expert", either directly (usually for pay) or in a community setting, like the Monestary, IRC, or Usenet.

Or, you can just bang on it a bit yourself until you find out that it breaks (or doesn't) to your satisfaction.

There's nothing I know that wasn't found out from one of the above. It's not rocket science (but even rocket science fits the above {grin}).

-- Randal L. Schwartz, Perl hacker