Most users chat on the IRC server in channel #FPL.

If you're new to IRC, the easiest way to get chatting is to go to mibbit, which is a completely web based IRC client that's very easy to use. Under "Connect to a Specific Server," choose Server, then type in #FPL under channel, then type in a nickname and press connect. If for some reason it connects you to the server but not the channel, just type /join #FPL in the server screen and hit enter.