send me a pm with what you're trying to hook up, and i'll try and provide you with the best advice i can.
likely scenario is:
standard dvd player (not upconverting)
yellow, white, red rca jacks --> video, then left and right audio. plug into video 2, and audio 2 inputs
hd cable box
could be an hdmi cable. plug that into your receiver. done.
could be coax. plug into your receiver. done.
could be component. plug into component 1 video and component 1 audio. done. best if you have an optical cable you can run also for 5.1 sound (it'll have a little spring loaded door on it, on both ends. cable is male-male, connectors are female)
run hdmi cable to tv from receiver, if possible. component if not.
