So here is an attempt at a version which is understandable and uses the proper names for everything.
Roughly speaking, there are two fairly standard ways of connecting to our IRC channel. They are to run an IRC client on your own computer, or to use the SRCF and run one there. Each has virtues and problems.
The first is easier, at least for absolute beginners. Depending on your operating system, fairly usable free IRC clients are Trillian or mIRC (for Windows), XChat (for Linux), or Colloquy (for Mac). Pidgin, which is a free IM client, will run on all of these and also do IRC.
To get any of these programs, google for their names and then download them. Once you've done this, you want to find the button for 'connect to server'. Enter 'irc.srcf.net', and hit connect. Once you're connected, type '/join #larp' into the text entry line and press enter, in order to join the channel.
The second method is a bit more complicated, but gives you some interesting extras - you can only use this if you are currently studying (or staff) at Cambridge University though! Firstly, you will need to sign up to the [SRCF], which you do by clicking the 'signup' link partway down that page and following the instructions. You should then shortly get an email with your account name and password.
Then you will need to have a terminal program of some type. If you're on Windows, the easiest one to acquire is [PuTTY]. On Linux or Mac, open your Terminal program, which is probably lurking somewhere in the Utilities part of the menu. On Android, you can use JuiceSSH?.
For PuTTY? users, you want to run PuTTY?. This will present you with a configuration panel asking you where you want to connect to. enter 'shell.srcf.net' into the hostname, and make sure the 'port' box says '22'. Then hit connect. It will prompt you for a username and a password, which you can enter from the email you got from the SRCF.
The process for JuiceSSH? is much the similar to for PuTTY?.
For Linux or Mac users, type 'ssh username@shell.srcf.net', where username is the username you had in your email. It will prompt you for a password, enter the one you were sent.
Now that you've connected, type 'passwd' and press enter, enter your current password, and a new one that you can remember more easily.
Then type 'screen irssi'. Once this has started up, enter '/connect irc.srcf.net', let it connect, and then enter '/join #larp'. This will connect you to the channel. If you want to change your nickname to something more informative, enter '/nick newname'.
When you're done for now, type Control-a, followed by d, and then enter 'exit'. Or simply close the window. When you want to get on IRC again, follow the first part of the instructions, but instead of entering 'screen irssi', enter 'screen -rd'. This means that you don't log off, so people can leave messages for you while you're away.
Legacy note: Various previous names for some or all of these machines exist. The correct approach is to SSH to shell.srcf.net, instead of whatever you might have used before, and use irc.srcf.net for your IRC server, also instead of whatever you might have used before. This will ensure things don't break suddenly and unexpectedly at some point in the future.
I hope this is comprehensible. If people wish to make it moreso, please feel free to do so. --Tea