/list Lists all current irc channels, number of users, and topic. /names Shows the nicknames of all users on each channel. /join <channel> Join the named channel. All non-commands you type will now go to everyone on that channel. /msg <nick>Sends a private message to the specified person. Only the specified nickname will see this message. /nick Change your nickname /quit Exits irc. /help <topic> Gets help on all IRCII commands. /who <channel> Shows who is on a given channel, including nickname, user name and host, and realname. /whois <nick> Shows the "true" indentity of someone Use this often to make sure you know who you are talking to, because nicknames are NOT owned so any number of people could use a nickname.
These commands should get you started on irc. Use the /HELP command to find out more about things on irc, or ask question of people... most would be happy to help you out.