Originally posted by ehrik.
Here's a quick mini tutorial on how to join IRC servers and rooms.
First you'll need a program like mIRC (Though it says it's not free, you can use it past the 30 day trial for free, this is also the most popular of the three I listed), HydraIRC (Completely Free), or Chatzilla (A firefox extension/plugin thing, free as well). There are also a ton of other IRC clients you can use such as Pidgin (Universal client that uses IMs systems like MSN AIM too) or xChat, etc, but they're all basically run the same way.
Next open whichever program you have, there should be a blank window with a line to type stuff in. It should look something like this:
Type on the line: /server irc.rizon.net , then press Enter.
Wait for it to connect, should look something like this:
The client will tell you when you've succesfully connected.
Now in the same window type in: /j #gametabs
Now you're done! You should see a new window open up, that is the channel window. Start chatting away.