What other coverage is available on the same topic? Most big news stories that are true get covered by multiple major news outlets. Google phrases to see who else covered the same story.
Keep track of trusted news sources and build up your own library of trusted sources.
Use fact checking sites like Snopes, Politifact, and FactCheck.org to investigate claims being made. Those links are below!
For images, you can do a reverse image search. Watch the video to see how it's done!