Register with Nickserv on BlinkenIRC
Register
Start by connecting to IRC, and make sure you are on the right IRC network (irc.blinkenshell.org). If you don't know how to do this see Info/IRC.
Change your nickname to the one you want to use in the future, the nickname you want to register. You can change nickname with this command: /nick <nickname>.
To register with NickServ use this command: (replace <password> and <email> with your desired password and a working email address)
/msg NickServ REGISTER <password> <email>
To get some additional help, type:
/msg NickServ HELP REGISTER
The password has to be at least 5 characters long. Beware that your password is case sensitive (which means foolish, FOOLISH or fooLish would be three different passwords.)
Now you have registered your nick with NickServ, and what's more, you are also already identified.
Identify
You will have to identify with NickServ every time you connect to IRC. You do this by manually issuing the following command or use SASL:
/msg NickServ IDENTIFY <password>
Irssi
The preferred method is to use SASL to authenticate at the same time as connecting to the IRC network.
You can create an alias in irssi so you won't have to type as much:
/alias NS /msg nickserv
To use this alias type:
/NS {IDENTIFY,REGISTER,HELP,or any other nickserv command}You can also make irssi automatically identify with NickServ each time you connect by issuing a command like:
/NETWORK ADD -autosendcmd "/^msg nickserv identify <password>;wait 2000" BlinkenIRC
You have to have a network named BlinkenIRC and use that network name to connect for this to work (ie /connect BlinkenIRC instead of /connect irc.blinkenshell.org.)
Have fun! And don't forget to join #blinkenshell and say hello to independence 
/join #blinkenshell