For video, you need two items. A Mini DisplayPort to VGA adaptor, such as
<http://store.apple.com/us/product/MB572Z/A>
and a VGA to composite video adaptor, such as
<http://www.amazon.com/PC-To-TV-Video-Converter/dp/B001CJOLBW>
For audio, you'll need a 3.5mm jack to RCA stereo cable.
(Note, the links are just examples of the type of device you need -- I don't know how well those particular ones work.)