well, only 1 wire is for the video, the other 5 are for the sound

(its 6 total, not 5 )
I'm really glad this isn't an Xbox 360 forum
Actually the 5 wires were in... not the yellow. I thought it was plugged in. haha Sorry about that everyone.
Red, Green and Blue are for Component, Solid White + Solid Red are for audio, Yellow is for Composite Video (SD/480i.. generally called 'AV input')
Although, it appears as if you've figured this out.
On a side note, since you have a high def. TV, you probably have a VGA input on the back panel, meaning you can get the Xbox 360 VGA cable (joytech, nyko and madkatz, as well as many other brands make them for $20 or so, Microsoft has one for $40) which will give you, in most cases, a sharper image with almost no jagged edges, when compared to component.
It will also allow you to up-convert DVDs up to 1080p (output depends on your TVs maximum resolution).. the Xbox 360 won't up-convert DVDs over component cables thanks to international laws that prohibit it, and component is usually more saturated with blue/dark blue/dark green than VGA, which gives a less than desired picture
Good luck!