There are a few useful commands on IRC that I've discovered. This is hardly original, but it's not yet posted here so I thought I'd share. Commands are typed exactly as entered. Italic text refers to items that you input (usernames, passwords).

/nick Yournick - Obvious. Sets your nickname. It is possible for a nick to be 'reserved' and thus require a password. Which brings me to my next command...

Nick Tips: There is a limit on characters in nicknames, 30 total. No spaces are permitted (see the IRC Quotes thread for what happened to me when I forgot that). Use "_" for a space. IRC doesn't let you set detailed away messages like AIM, MSN, Yahoo and similar. Instead, people change their nicknames to indicate their away status.

Example: Sovereign|Away (the "|" is Shift+Backslash). It's usually helpful to group your "away-nicks" (see below).

/msg NickServ IDENTIFY yourpassword - Tells the server that you are authorized to use the reserved nick you just chose using /nick. Used after the server tells you a nick is protected and registered. This happens either when you sign on (if your IRC client isn't set up to automatically reclaim your nick and identify itself) or when you change from an ungrouped, unclaimed nick to a nick you own.

/msg NickServ Register yourpassword youremail@yoursite.com - Registers the nick you are using when you type this command so that only those knowing the password (i.e. you) can use it and no one else.

/msg NickServ GROUP targetnick yourpassword - "Groups" a nick with another nick you control. Convenient because it allows a user to change amongst owned nicks without repeatedly having to use the IDENTIFY command above.

Example: I have the nick Jake, but I also want to have the nick Norm which is unregistered. Assume my password is "pandora." I would execute the following commands.
The code both registers Norm to me (the user) and groups it with Jake.

Now if I change between Jake and Norm, I won't be asked to identify myself. There is a 60-second delay between uses of the GROUP command.

/msg nickserv ghost yournick yourpassword
If you get disconnected and reconnect with "yournick_" use this command to get your nick back. Also good for nailing anyone who borrowed your nick.