If no wireless, then you need a cable to connect.

We have a linksys G2.4GHz wireless router for a year now, works fine.
(replaced our previous one what caused many problems=NetGear blech)

Ours Linksys has 4 ports for cables.

The yellow cord (ours is yellow) from the DSL modem goes to the
router in the main port (the one separate from the 4 access ports).

So you can do it by cables. We have my husband's work laptop set up with this router with a cable. My unit here goes into the router also. The laptop upstairs uses the wireless router. There is a procedure for hooking the wireless...our son did that for us. It has a monster password access and naming.
You only need this once...this is done on the net. My son set it up for us...you must have the directions? If not, go to their website. My husband says the router "talks" to the main frame somewhere to do the work...that this is pretty complex in theory but not so difficult to do yourself (I personally don't get most of it !) ...

If your DSL goes down you have to reboot in a certain order.
1) computer off
2) router off (pull the little jack out of the unit.
3) DSL modem off switch
4) DSL modem unplugged --the little jack in the back.

wait

reverse to log back on and wait about 2 minutes between each step in booting back up. Some time is needed while everyone talks to each other, so be patient.

My son is not answering his phone, so that's all I can do for now.