Reliable Resources.

The best news is from an earnest reporter who has multiple sources who independently confirm the information.   Over time this reporter would gain a reputation for providing unassailable information.  

There are obviously tainted organizations, which internally can have some good reporting.  Seperating the wheat from chaffe is where the work begins.

As the Devils Dictionary defines: REPORTER, n. A writer who guesses his way to the truth and dispels it with a tempest of words.