All man pages for modules get installed in /usr/lib/perl5/man/usr/, or
/usr/man/usr/ or .../man/usr/.  This is true whether using perl -MCPAN -e
shell or installing manually with perl Makefile.PL;make;make test;make
install.

The Makefile built by perl Makefile.PL contains
PREFIX = /usr
and also
INSTALLMAN1DIR = /usr/man/$(PREFIX)
and
INSTALLMAN3DIR = $(PREFIX)/lib/perl5/man/$(PREFIX)
However, when I type perl '-V:install.*'
I get:
installarchlib='/usr/lib/perl5/5.6.0/i386-linux'
installprivlib='/usr/lib/perl5/5.6.0'
installbin='/usr/bin'
installman1dir='/usr/man/man1'
installman3dir='/usr/lib/perl5/man/man3'
installprefix='/usr'
installprefixexp='/usr'
installscript='/usr/bin'
installsitearch='/usr/lib/perl5/site_perl/5.6.0/i386-linux'
installsitebin='/usr/bin'
installsitelib='/usr/lib/perl5/site_perl/5.6.0'
installstyle='lib/perl5'
installusrbinperl='undef'
installvendorarch=''
installvendorbin=''
installvendorlib=''

Details of installation:
Red Hat 6.2 with all updates
Did rpm --rebuild perl-5.6.0-1.src.rpm
then
rpm -Uhv --nodeps --force perl-5.6.0-1.i386.rpm

This makes perl difficult to use.