Please help me connect my Linksys wireless router.Thanks

I have cable as the internet provider. I can use either a desktop or laptop. But only one computer at a time. I bought a linksys Broadband router but couldn't make it work. I connected the USB cable to my desktop from the cable modem. Then the blue phoneline like wire to the router's internet port from the modem. But the wirless router is still not working. Please help. Thanks a lot