Head on over to the friendliest place in Progressiveland, on EFnet IRC Channel DailyKos.
It's easy, just download an IRC client for your machine - mIRC for Windows or Conversation for Macintosh OSX.
Their directions are easy to follow, but here is my own quick-start guide for Conversation, since I am Mac user:
This is gonna be a pretty simple glossing over, for more details, visit the Conversation Homepage at:
http://homepage.mac.com/philrobin/conversation/
Go to the above website, scroll down a page or so, and click the arrow under "1.4.2 for 10.2"
Once you download the program, you will have an icon titled "Conversation1.4.2.dmg" in the spot where your web browser downloads normally end up.
Double click it. On your desktop will appear another icon, this time titled "dossier sans titre" (?). Double click on it, and there's the program (icon titled "Conversation.") Drag it to your applications folder.
Double click on it. Up will appear a "Connection" box. Enter a nickname that you think will be unique, and 9 characters or less. No spaces allowed, but underscores (_) are ok. You should not need any password, leave that blank.
In the line where it says "Server" put in this, only because it seems to be working okay today:
efnet.demon.co.uk
If that one will not let you in, there is a page that has a list of known working servers for you to try until you find one that will let you in:
http://www.erienet.net/~circle/links.html
Once you have entered the server (leave the port box alone), click on the Connect button.
if successful, you should see a scroll of a lot of text explaining the rules for using their server. To summarize them, use common sense.
To join #dailykos (The pound sign is IRC-speak for 'Channel' which is another way of saying "chat room"), go to the File menu, choose "New Conversation", type "dailykos" into the box labeled "Channel" and hit the join button.
The channel window appears, with the list of who's already there in a pop-out panel on the right. Start talking by typing, when you're ready to send your text to the channel, hit Return.
Now you're on your own!