Some (mostly recent) pieces on using social media that I’d recommend:
General
7 powerful social media experiments that grew our traffic | Buffer Social
How The Washington Post works with its foreign correspondents to report via social media | Nieman Lab
Is Your Social Media Content as Popular as You Think? | Content Marketing Institute
How To Get Started With Google’s Accelerated Mobile Pages (AMP) | Search Engine Land
Using open soure social media sources in investigative work | Verification Handbook for Investigative Reporting
Facebook now ranks live video higher in the news feed | Buffer Social
How to see who has shared your content on Facebook | Search Engine Land
Facebook announces a WordPress plugin that lets publishers easily create Instant Articles | Nieman Lab
Instagram May Change Your Feed, Personalizing It With an Algorithm | New York Times
How to Tell Powerful Narratives on Instagram | Nieman Storyboard
7 ways news outlets can use Instagram | Journalism.co.uk
Twitter has changed. Get over it | The Drum
In defence of Twitter | Slack Communications
Jon Bernstein 