newbie help getting started

Im thinking about buying a Philips hdtv 30PW8402/37 HDTV monitor for just under 700 to hook up to my Comcast cable service, the question is do I need to buy a reciever to a) recieve anything b) recieve regular broadcasts or c) recieve HD broadcasts. Also is it possible to hook my PC in through my Radeon 7500 and if so how?

Thanks
Tabby

Comcast should have the HD version of their cable box and make an exchange with you. You don't need a receiver other than that. Don't know if there is a charge for the exchange.