We believe journalists should avoid using anonymous sources—ever. But if you or your news organization believes an anonymous source is the only way to get important information to your audience, you might start with NPR's thoughtful ethics guidelines.
The Reporters Committee for Freedom of the Press has a state-by-state guide to shield laws.
The Student Press Law Center has a helpful overview of shield laws.
DIVERSITY = ACCURACY
If your sources are all like you—similar outlooks, similar ages, same gender or race or ethnicity—then they probably don't represent your community very accurately.
Check out this section in the NPR Ethics Handbook for a thoughtful discussion about why diverse sources make for more accurate reporting.
How do you do a better job of integrating diverse sources into your reporting? Here are some tips (from SoundVision Productions' Science Literacy Project).
To increase the diversity of your expert sources, you might consult the Society of Professional Journalists' Diversity Source Book.
SEARCHING FOR EXPERT SOURCES
This article shows how to use Google Scholar or Microsoft Academic Search to find experts who are up-to-date and respected in their fields (from the Journalist's Resource at Harvard's Shorenstein Center on Media, Politics and Public Policy).
More than Helpless Victims or Dangerous Others
"What you lose in a voiceover sometimes is the nuance," says Daniel Alarcón, co-founder and executive producer of Radio Ambulante, in this discussion of the importance of including the actual voices of his sources. "Here, there's basically two tropes when we talk about Latinos: There's the helpless victim, and then there's the dangerous other. We're interested in stories that subvert those tropes.