assuming you have normal ADSL broadband (down your phone line) and not virgin cable broadband.
Go and get a ADSL wireless router, plug it into your phoneline and connect your computer to it using the cable to start with, follow the instructions that come with the router to enter your broadband user name and password into the router and it will connect and you will be online, if you don't know your user name and password you may have to contact your ISP, but these are normally your email address and the password you use to access emails.
once you've done that follow the instructions for setting up the wireless link and you should be able to dissconnect the cable and cary on surfing