Maybe you should have stayed in the helproom - that's where I saw this first :-}
Anyway, I'm going with the basics:
You need a broadband enabled line and a broadband ISP and for this you need to live in a braodband enabled area.
To connect to the net you are best with a modem / router in one: click here
PC World - D-LINK DSL-904 WIRELESS NETWORKING - This is what I was recommended and use now.
I connect the router to the phone socket with a microfilter. The router is also connected to the PC in my office via a cable.
Downstairs I have another PC which has a USB wireless antenna connected - this picks up the signal from the router in my main office.
In my bedroom I have my laptop and connect wirelessly to that to listen to radio and check mails etc.
Any friends who come can also use it on my spare laptop.
All, any or none of these can be connected at any time. There is no need for any individual PC to be switched on as long as the router/modem is on. As it happens, my main PC runs 24-7 but there is no reason for that other than that I want it to.
The modem/router that I suggested above has enough to connect to the main PC and also one wireless antenna. Depending on the PCs that you have, you can either get USB or PCI (interal) or (for laptops) PCMCIA antenae.
Hope this has not made you even more confused!
And yes, it is pretty straightforward to setup!