Use the library catalog to find books on "Generation Y" millennials or "young adult consumers."
Mine the Pew Research Center's many studies and reports on the Millennials. The Pew Research Center is a highly respected, nonpartican, often quoted, nonprofit that does polling, social science research and analysis of social issues and trends.
Search Business Source Premier for articles about the consumer behavior of students OR young adults OR adolescents.
The following databases offer market research reports on industries or product catagories MarketResearch.com or Mintel may have profiles on marketing to teens, young adults and students too.
Mintel (consumer goods & services)
MarketResearch.com (consumer goods & services)