/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.
These commands should get you started on irc. Use the /help command to find out more about things on irc, or ask someone, most would be happy to help you out.