There are several bits of advice that I give any Perl newbie who listens, and which I'd certainly give myself if I could meet my younger self.

• Learn by coding a piece of software that you actually use yourself
• There's an incredible amount of Perl wisdom in the perldoc man pages and on perlmonks. Embrace it!
• If you're unsure about a construct (how a built-in function or some syntax behaves), experiment in a small, autonomous script
• Get involved with the Perl community as early as possible. It's very friendly, and its collected domain knowledge can make your life much easier
• Collaborate with others
• Use the CPAN.
• If nothing you change in a file seems to have any effect, check if you're really editing the same file you're running, and if you're running it on the same host as you're editing (easy to overlook if you have ssh sessions over a fast network)