Here's a couple of interesting resources about youth and that. Three billion is a selected feed of youth/marketing news from around the world. (The name comes from the fact that there are three billion people in the world under 25). And then there's the BBC World Service's Generation Next project. All kinds of stuff talking about young people including a survey they did with under 18-year olds in 10 cities around the world, splendidly it's a little less western-centric than most of these things.