Ok, first off, IRC. its essentially an IM with many more capabilities. Also, it is more or less a chat room, with being able to talk to everybody at the same time, in one conversation. In other words, if you want to have a conversation with someone that is off topic of the blog post that brought it up, you can take it in there. Plus no more spamming F5 for a response.
Its free and fairly simple to set up.
First off you need to download the client found here   http://www.mirc.com/; Just click download MIRC, it will be free and after 30 days you will have to watch an add for a few seconds.
When starting it will as you to register, ignore that, just click continue or cancel (something like that), after that point use this guide here http://www.magic-league.com/guide/mirc.php.
Now there are slight differences from those screens and the current version. The only one really is The earth with # is a heart instead. Same button, different Icon.
First thing is to put in your name and email (these 2 could be anything), nickname, you can leave alternative blank. Then on the left side its says connect, and inside it should say server. Click that and the menu on the right whould change to a list of servers. You want to go to the QUAKENET server and inside that click random server.
Hit ok and you should connect to the server, from there a pop up should appear asking which channel you want. Type in Avatar_Wiki in the empty bar at the top, hit ok and there you go