Alright
-hook the cable box and dvd player up to the AV reciever with hdmi
-Hook the revievers output to hdmi 1 on the tv
-get a dvi to hdmi cable and use it to hook the computer to hdmi 2 on the tv
-if your sound card has a digital output, get the apropriate cable (TOSLINK or Coaxial) and hook it up to AUXILARY on the reciever. if it doesnt have a digital out, hook it up with a 3.5mm headphone jack to RCA audio cord to the AUXILARY on the reciever
-Get some good speaker wire and hook up speakers to reciever.
That is what I would do.
John