Hi,
I hope I do not look too nasty but... Try to have a look at the Net::IRC module. It does that for you and more beside :))

As it said inn the module man page:

use Net::IRC;

$irc = new Net::IRC;
$conn = $irc->newconn(Nick    => 'some_nick',
                      Server  => 'some.irc.server.com',
                      Port    =>  6667,
                      Ircname => 'Some witty comment.');
$irc->start;
[download]

By the way, doing it through Socket, implies reading very carefully the IRC rfc.