Current Perl documentation can be found at perldoc.perl.org.

Here is our local, out-dated (pre-5.6) version:

Here are the suggested ways of modifying your include path:

    the PERLLIB environment variable
    the PERL5LIB environment variable
    the perl -Idir commpand line flag
    the use lib pragma, as in
        use lib "$ENV{HOME}/myown_perllib";

The latter is particularly useful because it knows about machine dependent architectures. The lib.pm pragmatic module was first included with the 5.002 release of Perl.