What is best way to install Perl modules?

You may want to use the modules shipped by your distro, so that they're updated automatically when you run an update of your system,
although they're generally slightly older than the most recent modules you can find on CPAN.

Try a
yum search perl | less
or
yum search perl MODULENAME
to find out if a module is available on Fedora as a separate module.

Also,
rpm -qa | grep perl
may help you find out what modules you have installed (this will not list core modules or modules you installed via CPAN, though).

I find modules installed via yum more manageable, but it's just a matter of taste.
I fallback to CPAN whenever I need the latest version of a module or a module which is not packaged with the distro, although this rarely happens.