Using CPAN the first time

The first time you try to install anything from CPAN, you will be presented with a simple set of questions to answer to configure the installer.
Basic install of module:-

perl -MCPAN -e 'install Chocolate::Belgian'

If you have to, you can force an install, this should be a last resort as the output from the failed install should give a good clue about why it has failed:-

perl -MCPAN -e 'force install Chocolate::Belgian'

Reconfiguring CPAN

If for some reason you need to reconfigure the CPAN installer, the config is stored in a file called Config.pm which is most likely in a location such as /usr/lib/perl5/5.8.6/CPAN.
The usual reason I have had for editing this file is to change the proxy settings:-

cat /usr/lib/perl5/5.8.6/CPAN/Config.pm

Deleting this file will force the CPAN installer to rerun it's Q&A session.