One way in which the media influences us is by telling us that a certain body image is correct. Both young girls and boys are pressured by the mass media to look a certain way. Images of the "perfect body" are projected everywhere, from TV commercials to Internet ads.
There is an article from the International Journal of eating disorders that discusses these effects:
Cusumano, D. L. and Thompson, J. K. (2001), Media influence and body image in 8–11-year-old boys and girls: A preliminary report on the multidimensional media influence scale. Int. J. Eat. Disord., 29: 37–44. doi: 10.1002/1098-108X(200101)29:1<37::AID-EAT6>3.0.CO;2-G
If you are looking for other sources, my advice would be too look up "media and society" using Google Scholar. That's one of the best ways to find reliable articles from reputable sources. There are a lot of sources that date back to the 1990s, but I think you would want to look for a source after 2000. The media has evolved in the past decade with the growth of social media and increased access to the Internet.