Please note this AV cable is for the original NES model, NES-001. The NES "top loader" which was smaller and came out later, does not have the jacks for an AV cable and uses only an RF switch.
Instructions to hook-up to your TV: Connect one end to your TV Audio/Video input, and the other end to the ports on the right hand side of your NES as follows; red (audio) to red, and black (video) to yellow.