The Kaiser Family Foundation has been conducting a national survey on the media used by children from 8 to 18 y.o. The findings were just announced today. You can find the full details
here (press release, prsentation, summary, and more).
Here's the good news: book reading has actually increased in the last 5 years, both in the number of kids reading and the amount of time spent (p30). Unfortunately, newspaper and magazine reading decreased. I'm not surprised; we all know Old Media is in trouble.
press release
report