Cable box are RCA & S-Video, I think. Where would the other cable hook up to? Best Buy said that is all that I need to run my TV, DVD & Surround Sound. Sorry, but I don't know anything about this stuff.
If the cable box only has 1 set of outputs(double check though), hook rca/s-video to TV. On back of TV you should have a digital coax and rca's as an "output". Either get a digital coax cable or rca and hook that up to your stereo input.