The news editor for SLATE does a good job of explaining what "news literacy" is and how it's designed to create more critical news consumers.
Have you seen the TED video: How False News Can Spread? It's a concise look at news, in a social media age.
Meanwhile, the NYT Learning Network recently posted this piece with ideas and suggestions for engaging students in current events.
Lastly, The American Society of News Editors (ASNE) and the Journalism Education Association (JEA) in partnership with the Donald W. Reynolds Journalism Institute offer free news literacy lessons for English/language arts, science, math and social studies teachers to use in secondary-school classrooms. The lessons are available at WhyNewsMatters.org, SchoolJournalism.org and jea.org. Funding for the project was provided by the Robert R. McCormick Foundation.
Thanks. I'll use many of these resources some time in the coming year.
RE your title question: It's not a matter of trusting news sources (I generally don't!) but of verifying and not relying on limited sources.