Content type
This could be research news, news from friends through social media, newspapers etc..
They often tend to be short messages leading to other links. Sometimes, they are followed by discussions.
Research news
Besides internet journals and pre-print collections, twitter feeds and blogs of researchers tend to be a very good source of research news.
Lectures and course-notes are considered separately.
Curation of articles and comments
News can be chosen, curated, arranged and presented either by a small group of professional editors (Eg: BBC, Time, etc..); or by a democratic process where a huge group of readers vote articles up and down (Eg: Reddit, Digg).
Comments may also be curated by an editorial process (presented in the form of letters to the editor), or they may be curated and rated by a democratic system of votes (as in the case of Reddit, Ted talks, Youtube).
Selectivity, filtering
To get good return for the time spent following news, filtering and curation is essential. Good sources, from experience are: reddit, ted talks, podcasts such as Planet Money, BBC.
Sometimes this must be done manually. For example, in Facebook, classify people depending on the topics they post about, and zealously unfollow news feeds of people who consistently reduce the quality of your combined news feed.