From a little old unix admin:

IO::Socket
FileHandle
File::Find
DBI ( et all )
Getopt::Std
SNMP, Net::SNMP, SNMP::Session (*ick* but necessary)
Net::(Ldap | SSH | SCP | FTP | Telnet)

Date::Manip
I think that about sums it up for the admin side..On the reporting side

CGI ( though I almost loath HTML, manager types like it)
GD::*, as well as the chart family and 3D stuff in there as well



MMMMM... Chocolaty Perl Goodness.....