If you want to put output audio, then you're going to have to take a cable from your sound card to your TV.
If you have a normal soundcard with just regular old headphone outputs, then you're going to have to go to radio shack and buy a mini-jack to RCA converter. You can use these RCA ends (composite, the red and white ones) to get audio from your sound card's output to your TV. I'd recommend using the Line-Out, as you don't need an amplified port for audio-in.
For outputting video, you can either use S-Video or Composite (the one that looks like a keyboard plug, or the one that's the yellow RCA jack, respectively). S-Video will give you a MUCH higher signal, but the cables are a bit more expensive, and not all TVs (older ones don't) have S-Video inputs.
I'll leave recommending stores to other people.