Mashable.com is a really helpful resource for understanding hot topics, hearing about current trends, finding guides, etc., in the realms of social media, digital media, technology, and Web culture.
Here are a few examples of articles that you might find useful on Mashable.com:
This is updated weekly and explains what the majority of Twitter users were talking about. It also offers background/context about the most-tweeted topics instead of merely listing them.
Here are examples of social media tutorials on Mashable:
The Facebook Guide Book
The Twitter Guide Book
And if you are on Facebook and want to stay up-to-date with Mashable’s current articles, you can “Like” them on Facebook so their posts appear in your newsfeed.