Any device that you have access to will suffice.
see this post for comments.
Personally, I like the Netgear or Belkin brands while many insist upon Dlink.
If at all possible, get a G mode router with the MIMO feature
(many in, many out). It means there's better radio transmission/receiption.
ok, get the manual and find the SETUP instructions.
Your first step is to make the router fit between the DSL and your system
and keep your Internet access.
Disconnect your system from the DSL cable.
Connect the Router to your system and power it on.
Use your brower to access the router configuration;
you need the Router Default Address, the admin id and the default password.
Enter
http://192.168.0.1/ for example -- yours may be different
enter the ud/password pair
you should get a page with links on it for configuration details like
WAN setup, LAN setup, Wireless Setup, Administration ....
At this stage, document your router LAN address, admin id
CHANGE THE PASSWORD NOW!
Save it and you may need to restart the router (power off/on) and to
log back onto it via the browser.
Once this is working, you can cable the DSL to the WAN side port
(using an Ethernet cable or a USB if you have to).
The router will setup the WAN side for you and your system should be able to
surf the net.
Post back when this is done our when you have issues and we'll continue with
the wireless setup.