Reporters Committee for Freedom of the Press
For more than 40 years, the Reporters Committee for Freedom of the Press has provided free legal advice, resources, support and advocacy to protect the First Amendment and Freedom of Information rights of journalists working in areas where U.S. law applies, regardless of the medium in which their work appears.
In particular, see the First Amendment Handbook.
Also, see libel articles in The News Media and the Law, Summer 2011 [legal, topic human rights]