What to do...
right, so you want to download a program to access my chat room. this makes it easier, and is what most people do.
first, download mirc here. it's a small program, won't take that long to download. once you have downloaded it, install it onto your machine.
now you should find mirc in your start menu, so click on it. mirc will start. from here you have to set up mirc so it knows what network and chat room to load for you. just click on the box with the photo of the person who made the program, it'll go away.
now an options screen will open up. fill it in as i have in the next three screen shots.

i have filled it in for myself. make sure irc network and the box below it are set. for your full name put what you want, email address doesn't have to be real if you wish to fake it. for your nickname choose a small name with no fancy characters, like mine, 'keot'. the alternative nickname is incase someone else has your nickname already. mine is keot`.

make sure connect on startup is checked, reconnect on disconnection is checked, and uncheck the pop up connect dialog on startup.

the perform section is a list of instructions for mirc to follow every time it connects. put /join #mtuk in it, and make sure enable perform on connect is selected. this means when mirc connects, it'll join my chat room, #mtuk.
you can now go through the rest of the options and have a fiddle if you want, but you've put what you need to put in now. click ok, and then click the connect button, as shown below...

now a load of details will fill your status screen, and after awhile, another screen, #mtuk will launch. this is my chat room. don't be afraid to ask if you don't know something (in irc of course...)

if it did not connect...
nickname already taken - type "/nick mynewnick" without the quotes. this error has come up because someone else has already got both your nickname and alternative nickname. on quakenet, you cannot own a nickname, so if yours is taken, tuff, choose another.
if irc doesn't seem to do anything - check all your options are set correctly. if it doesn't work, then your computer may need some more settings done, because it has a firewall. ask your dad or the the person that set the machine up in the first place.