There are many web resources to learn more about this demographic. Check out this site, written from a human resources perspective.
Gen Y children have been wanted, valued and coddled from birth. They have lived highly structured lives. From their preschool days they have had scheduled playgroup dates, and participated in team sports, music lessons and a wide range of stimulating activities. Parents have micro managed their schedules and remain highly involved in their children’s lives.
Here's a good primer on Gen Y and their links to online culture.
Those born after 1982 are the most media savvy, educated, and wired people to have ever walked the earth. They are also the largest trend-setters since the Baby Boomers.
A recent NPS meeting also looked at Gen Y and why the Park Service should care about this important demographic.
And a bit more background here.