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:
10 Tips for Posting on Your Brand’s Facebook Page
10 Rules for Increasing Community Engagement
Top 10 Twitter Trends This Week
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.
“Mashable–Social Media” on Facebook (Note: Mashable has other categories you can like on Facebook, such as “Mashable – Web Video”)