The hub of any good home theater system is the AV receiver, which controls the audio and video information of everything else connected to your system, from speakers right on down to DVD players and video game systems. The first thing you must do, however, is connect your TV to your receiver.
Take a look at the back of your AV receiver. The goal here is to see exactly what kind of inputs your receiver has, and which of those your TV also has. Possibilities include component cables, composite cables, S-Video and HDMI. See what your options are and purchase the appropriate cables.
Choose your preferred method of connection. The recommendation is to buy the highest quality cables, which will enable you to experience the highest quality audio and video available. In this particular case, an HDMI cable is going to give you the best audio and video, followed by S-Video, component and then composite cables.
Plug one end of your cable(s) into the appropriate output on the TV and one end into the appropriate input on the receiver. This will transfer the signal from your TV through your receiver which will allow you to control it along with all of your other home theater components using the same device and remote. If you've chosen an HDMI cable, there will only be one cable to plug in, as the audio and video information is transferred using the same cable. S-Video, component and composite will all require multiple cables to be plugged into the correct inputs to properly receiver audio and video information.
Select the correct input on the front of the receiver. When you plugged your TV into the back of your receiver, you plugged it into one of several sets of similar inputs. These exist so you can plug multiple devices into the same receiver. Selecting the correct input allows you to use that particular device. Hit the "input" button that activates the inputs the TV is plugged into.
Audio and video cables can be extremely expensive.