I've copied most of this from the FAQ thread. I'll add more as we go along and if anyone else has any I missed please feel free to add them here.
First registering your nick. If you aren't already registered with nickserv, then type the following: /msg nickserv register YOUREMAIL YOUR PASSWORD (Don't write YOUREMAIL or YOUR PASSWORD. You change YOUREMAIL for your email address, and YOUR PASSWORD for the password you wish to have)
If you don't want to register your nick, or haven't, and go into chat using the Java link, then you will enter under the name Guest. To change this type: /nick name-you-want-to-use So, if you want your nickname to be "Henry", you can type /nick Henry
If you want spaces in your nickname, you have to use hyphens or underscores. If you want to be Henry the 8th, for example, you could type type /nick Henry_the_8th
If you want weird characters, you might be out of luck. Try it and see
Note on etiquette: really long nicknames are inconvenient for many of the other chatters, because our window size changes. Also, it's often nice to use your AW user name, because that lets us all know who's who, and maintain information/contacts between places. Not at all required though.
/me lets you do "actions". The form is /me <action>. If I want the chat room to say "Shweta jumps up and down" I can type /me jumps up and down. Note the third person - it's a little counterintuitive, but you want to use third person because /me is replaced by your nickname.
/msg lets you send a private message to another chatter. The form is /msg <nickname> <message>. So if I want to send a messsage to Pthom (whose chat room nick is Peter), saying "psst! Your epidermis is showing!" I would type /msg Peter psst! Your epidermis is showing!
Now with some irc clients (including javachat), /msg will open a private chat window that you can then just type into. You can alternate between that window and the main chat room - how depends on your client.
If it doesn't do that for you, and you want a private window, you can use /query -- which lets you open up a private "query window". The form is /query <nickname>. So, if I wanted to open up a whole new window to talk to just Peter in, I'd type /query Peter - and then a window would open up, and I could type in it.
If you didn't want to open a new window for either you or the person you want to message you can use /notice <nickname> <message> . So, if I wanted to message Peter with the above message I would write /notice Peter psst! Your epidermis is showing!
/whois lets you get some information on another user (like, for example, if someone has changed their nickname into something odd, and you want to know who it actually is). The form is /whois <nickname>. So if I want to know who this Peter guy is, I could type /whois Peter
If I do this I get the following:
--- [Peter] (petom1234@StarXXXX.cable.com) : peter
--- [Peter] @#AbsoluteWrite
--- [Peter] Justice.OR.US.StarChat.Net :Conscience is the chamber of justice. -Origen
--- [Peter] End of WHOIS list.
Line one means "This is Peter". This might be useful if he'd changed his nick to SpaghettiMonster. Then if I typed /whois SpaghettiMonster it would say:
--- [SpaghettiMonster] (petom1234@StarXXXX.cable.com) : peter
And I would know that SpaghettiMonster was really Peter in disguise.
Line two means "He is in the channel #AbsoluteWrite, where he is a channel operator" (@ means channel operator). Of course if you too are in #AbsoluteWrite, you already know this.
Line three means "He is on the irc server called Justice". This information is only useful under a bizarre set of conditions.
Line four means "I'm done now."
Now I'm not sure if this works for everyone, but if I type /whois <nickname> <nickname> I can find out how long someone's been idle. So if I type /whois Peter Peter I get an extra line:
--- [Peter] idle 00:00:12, signon: Sun Feb 25 14:08:42
This is useful if you're trying to talk to someone and they aren't responding - if it turns out they've been idle for an hour or more, you might not want to hold your breath.
/ping lets you know how long it is taking your messages to get to someone. The form is /ping <nickname>. So if I type /ping Peter I get something like this:
--- Ping reply from Peter : 0.83 second(s)
This is only useful if you think you're lagged, or if you think someone else is - if that number is over 2 seconds, there is definite lag. Note: this command spews junk into the other person's window, so do not use it unless you need to!
Okay! That's all for now, folks