Hello DJ,
Depending on your TV's capabilities, you will need either an S-Video cable, which will work with a TV which has an s-video jack, or if what you were referring to as the yellow jack looks like an RCA type connector (as would be found on the back panel of a stereo), then you can buy a composite cable. If your TV is compatible with S-Video, I would very much reccommend that over the composite connection, as you will get much better quality out of it.
Unfortunately, you may be disappointed with the quality video out provides. I recently tried to connect my Radeon 8500LE 128MB card to a Sony Trinitron TV which is S-Video compatible, and that yielded horrible quality (only 1024x768 resolution and a very fuzzy picture). This TV was not made for video out, and is a few years old, so you may have better luck than I did.
In any case, good luck getting it to work and make sure you download a new video player (like DiVx) if you're planning on using this for video playback since I think Windows Media Player has some kind of copyright protection feature which keeps any kind of video (regardless of the source) from displaying on TV out. At least that was my experience.