Get an RSS reader (I use Omea from JetBrains but there are others out there), go to a variety of websites that you find interesting, find their RSS feeds page (this is NewScientist's) and copy the interesting RSS feeds to your RSS reader.
RSS Feeds are usually shown by this icon.
Your RSS Reader then downloads articles as they are posted, you scan the articles for interesting ones, and post them. This lets you post new, interesting articles as they come out. Check that no-one else has already beat you...
Other option, find new and interesting content wherever you like, including making your own.