For clarity:

dpetrov@vaio:~$ cpanm Catalyst Catalyst::Devel
[download]

Here 'dpetrov' is the current logged in user and 'vaio' is the hostname of the system. '$' is the prompt symbol and '~' is the path to your users home directory in bash (e.g. /home/marto in my case).

You don't type this in, it's simply for illustrative purposes. If you've followed the steps you should be able to install modules without issue, from your command line:

cpanm Module::Name
[download]

Substitute Module::Name for whatever you want to install.

Thanks a lot, it finally works :) I tried to install ExtUtils-PkgConfig-1.16 but it failed at the configuring step. Is there a way to install it anyway?

Glad that worked, can you post the contents of the cpanm log file for the failure, it's too hard to say what's wrong otherwise.