Gist to help someone (Usually me) setup irssi after a fresh install. All changes mentioned here can be made directly to your .irssi/config file also.

Basic irssi setup walk-through

Typically used irssi config

### Large portions shamelessly copied from https://wiki.archlinux.org/index.php/Irssi (Thank you Arch Wiki )
# Please refer to the aforementioned link for more detail and customization.

# irssi has a pretty good default config that you don't usually want to mess with much
# A couple of basic things that are needed are specified here. Type /set to see a complete list of modifiable parameters.

# BASIC SETUP:

/server add -auto -network fn irc.freenode.net # fn is shorthand for FreeNode, use anything you like though 
/set nick your_nick
/set user_name your_user_name
/set real_name your_real_name
/network add -nick IRC_User_name -autosendcmd "/msg NickServ IDENTIFY passwd" #where passwd is your password
/channel add -auto #channel-name fn 
/save 
/quit 

# restart to see if all is well.




# ADDITIONAL CONFIG.
# You'll have to do a /save after you're done to save your new config to the config file.



# enable Automatic logging of conversations. Depending on space constraints you may or may not want to do this.
# *Or* you could setup cron to periodically tar the logs, mail them to you, and then clean the old ones. Your choice. :)
/set autolog

# Ignore quits and so forth
/ignore * joins
/ignore * parts
/ignore * quits

# Irssi usually picks up the proxy from the *_proxy variables, but if you feel the need to manually configure, use
# NOTE: I've never used these and never needed to.
/SET use_proxy ON
/SET proxy_address <Proxy host address>
/SET proxy_port <Proxy port>





Brief Commands List:

# Type /help for a full list of commands

# Connection

/server		/s	These change the server of the current network.
/connect	/c	open a new connection to a server, use to connect to multiple servers simultaneously (C-X to switch).
/disconnect	/dc	These close the current connection to a server.
/names			List users on the channel.

# Movement

ALT+(1-0,q-p,etc)	Changes the active window. Or use Ctrl+n for the next window or Ctrl+p for the previous window.
/window 1	/w n	Takes you window n. Windows are numbered across (1,2,3..0) and then start on the next row down (q-p)
/window close	/wc	 	These close the current window.
/window move 1	/w move 1	These move the current window to the first window position.
/layout save	 		This will save the current window positions for the next time you start irssi.

# Miscellaneous

/set	 This shows a list of all your current settings.
/help	 This provides a helpful description/explanation for whatever parameter provided.
/alias	 Lets you create your own shortcuts.

# Useful commands
/ctcp some_nick time 			Get's you someone's Time and Timezone. They'll know you sent the command though.
/part channel_list parting_msg 		Quits current channel
/clear					Clears the current window



# Useful related links:
http://quadpoint.org/articles/irssi/ # Using irssi and screen.
https://wiki.archlinux.org/index.php/Irssi # Arch Wiki documentation for irssi
http://askubuntu.com/questions/61549/how-do-i-configure-irssi #Here's a well configured .irssi/config file should you need it.