This should help. Straight from their website http://www.ceruleanstudios.com/support/index.php?s=IRCHELP
Click the Trillian Tab > Connections > Manage my Connections... Add an IRC connection, filling out the boxes with the appropriate IRC Channel/Server info. Click Connect. Thats the basic idea of what the link said. I only posted the link instead of telling you because it has pictures there and isnt very hard, only 4 real steps.
Oh ok, wasnt sure because you never said that Server: irc.quakenet.org Channel: #gamerenders Port: 6667 Enjoy.