This site includes some items related to media effects - the idea that people might imitate behaviour they have seen in the mass media:
Ten things wrong with the media 'effects' model
Article by David Gauntlett.
First published 1998, revised 2001, 2005.
Moving Experiences, 2nd edition: Media effects and beyond
Book. Introduction available online.
First published 1995, second edition 2005.
There are also a range of resources about media influences - less simplistic ideas about the ways in which popular media might play a role in the shaping of identities:
ArtLab website, about new creative methods for exploring identities and influences.
Media, Gender and Identity: An Introduction
Book. Various articles and interviews available online.
Older identity page with a number of resources.
Older role models page with a number of resources.
Older Anthony Giddens pages, also useful for thinking about media and identities.