Current Perl documentation can be found at perldoc.perl.org.
Here is our local, out-dated (pre-5.6) version:
The Data::Dumper module on CPAN is nice for printing out data structures, and FreezeThaw for copying them. For example:
use FreezeThaw qw(freeze thaw); $new = thaw freeze $old;
Where $old
can be (a reference to) any kind of data structure
you'd like. It will be deeply copied.