To take advantage of broadcast HDTV programming, you will need an antenna connected to an external HDTV receiver. Check your local broadcasters for HDTV availability.
The satellite dish comes with a receiver that connects to one of the inputs on your Hitachi set. Depending on the satellite receiver and which Hitachi model you have, you can hook up via component connections for high resolution video. Some services also offer HDTV programming, which many Hitachi models are ready to display.
Hitachi sets all come with multiple inputs that accommodate other video components. Most models feature both composite (direct video) inputs, S-Video as well as component video inputs. Simply switch between inputs with the TV remote control.