Firstly, make sure you get a DSL router - thankfully most manufacturers badge these as "cable" routers now. We have a Belkin, but I'm not particularly impressed with it. If I was to get another I'd probably try a Linksys or NetGear. PC World sell all of these.
What I do like about the Belkins is that they are "usually" really easy to set up. Instructions are clear and concise.
Next thing you will need is wireless cards for laptop and pc ... last time I looked these were a LOT cheaper online, but if you really can't wait, then take the plastic (or a fat wallet) 'cos these are one of the items I believe PCW rip you off with (although I could be wrong
). Just make sure that whatever you get it is compatible with the router. If you ask the staff they'll be able to point you in the right direction (most of the PCW staff know a fair amount more than they did a few years back LOL).
Oh and finally ... have a look for the routers that come supplied with one wireless card also ... you may be able to save a little bit of dosh that way
One other thing on the setup ... all the cable routers I have installed, you nearly ALWAYS have to switch the cable modem OFF during install.
During the install when it asks you to now switch on the router, switch the cable modem OFF and leave it off for 20 - 30 seconds. Now switch it back on again followed by the router. (At least I think that's the way round I did it?!). Don't worry if it doesn't work first time either ... just switch EVERYTHING OFF, leave it for a minute or two and then switch it all back on again.
Sorry - this is turning into a bloody saga ...
One more thing ... MAKE SURE YOU SECURE YOUR NETWORK.
Last time I installed a router the security is configured to be as good as disabled "out of the box". But if you read the accompanied manual you should be able to figure it all out
Usually I configure a WPA-SK key, and hide the SSID as soon as your laptop and PC have connected once. That way, your network isn't broadcast to your neighbours. And even if it is, they'll need to enter a password to use your network then ... unlike someone locally to me
so when my wireless network fails, I have been known to use theirs (briefly)
Pete