Hi, you can start with a 1/8" <-> composite adapter. It's cheap and works. The only big problem with this is that you will need to turn up the volume to compensate for the fact that the headphone jack does not output line level. I do this with my iPod. If I turn my iPod up all the way, then I have to set my stereo somewhat higher than I normally would, but it comes through nicely.
This is the type of cable -- can get this at Best Buy, Radio Shack, etc... too:
This is a really nice one
from Monster Cable
This is a much cheaper one...probably just as good:
On Froogle