irc HOWTO for first time users

irc (Internet Relay Chat) is just another chat service like yahoo, but in contrast to other services irc is very mature and sophisticated. It has some rules and those has to be followed while chatting in the room.
An irc channel is like a chatroom. Your login name is called nick. Unlike yahoo there are many independent irc servers worldwide. And you need to register seperate nick on each server to be able to log on to it.

For using irc you will need software like Xchat
There are many other free softwares for irc, in linux/bsd as well as windows.

Steps to get going with irc.
1.Open the irc software and find where is the command prompt(usually you will be using commands instead if point and click GUI)
2.irc commands begin with a /
So type in server name, issue following command
/server irc.freenode.net
3.Choose your nick
/nick yournick
4.Register your nick
/msg nickserv register yourpassword
here nickserv is a bot which will authenticate you.
5.Now join a channel(i.e. chatroom). Any channel begins with a #
/join #linux
or
/join #ubuntu
or
/join #electronics
6.Now you can chat in the channel and send personal messages to others.
However note that if your behavior is found improper then channel-operators have right to throw you out of room and ban you. So make a habit of acting friendly.
Following is a good read on irc
Ubuntu-in irc guide
GNU guidelines

Now next time you will just type in
/nick yournick
/msg nickerv identify yourpassword
/join #linux

There is no such concept as *log out* in irc. Just disconnect from irc server and close irc application, you're done.