/away When you're called away to put out a grease fire
in the kitchen, issue this command to let others know
you're still connected but just away from your terminal
or computer for awhile.
/help Brings up a list of commands for which there is a help
file. You will get a "topic:" prompt. Type in the
subject for which you want information and hit enter.
Hit enter by itself to exit help.
/invite Asks another IRC to join you in a conversation.
/invite fleepo #hottub
would send a message to fleepo asking him to join you on the #hottub channel. The channel name is optional.
/join Use this to switch to or create a particular channel, like this:
/join #hottub
If one of these channels exists and is not a private one, you will enter it. Otherwise, you have just created it. Note you have to use a # as the first character.
/list This will give you a list of all available public channels, their topics (if any) and the number of users currently on them. Hidden and private channels are not shown.
/m name Send a private message to that user.