First of all,

to Cable forum.
Secondly, I know you said you didn't need wireless but for the difference in price it's worth buying one now and then you have the facility if you want to use wireless later. You can still use a wired connection to up to four PCs with the router below.
The Linksys range are good, and this one would certainly be compatible:
http://www.amazon.co.uk/exec/obidos/...586941-4057200
As for instructions:
- Switch everything off (Modem, PCs etc)
- Plug the router in (but leave it switched off) to your Modem and to the ethernet ports on your PCs
- Turn the Modem back on and leave it for the lights to settle
- Turn the router on and wait for the lights to settle
- Turn the PCs on
Linksys routers come with DHCP enabled as standard (they automatically assign IP addressses to your PCs) so you don't need to worry about that initially. The only thing you will want to do in the first instance is go through the router's settings and make sure it is secure (changing passwords, restricting the wireless access etc).
Basically, follow the instructions that come with it on the quick start sheet and it should all work fine. You
must turn everything off and back on as I've described above though or it just won't work.
If you get any problems just post back once you've got the router and I'm sure someone will talk you through the process.