Social media had its fair share of ups and downs in the last year: After much hype-and to much disappointment on the stock exchange- Facebook finally went public. Google's social network, Google+, turned 1-year-old in June, and Google later announced that more than 135 million people visit the site every month.

Though Google+ saw an increase in its user base, the search company was plagued most of the year by antitrust investigations by both the Federal Trade Commission and the European Union. The year also saw the major social networks rollout a number of improved interfaces and new features, including Twitter and LinkedIn, as well as the explosive rise of Instagram and Pinterest.

Here's a look at 12 of the most popular stories and slideshows about social media that appeared on over the past year.

5 LinkedIn Tips for Career Success in 2012 January 5, 2012 From sprucing up your profile to branding yourself as an expert, here's how you can better use the professional social network to set you on the path to success.

Your Complete Guide to Facebook Timeline January 25, 2012 Whether you like it or not, Facebook Timeline is becoming mandatory. Here's's complete guide on everything you need to know-including first steps and privacy changes-to help ease the transition.

Facebook IPO: The Heftiest Paydays February 2, 2012 With a possible valuation of $100 billion, Facebook's IPO filing could make a lot of people very, very rich (or richer). Here's a look at the breakdown of who could get what, from Mark Zuckerberg to Bono-yes, Bono.

A How-to Guide for the New Facebook Business Pages March 1, 2012 Timeline has finally come to Facebook Pages. Here's a look at how the features differ from your personal Timeline and how you can best optimize them to market your business and communicate with your customers.

11 Promising Enterprise Social Networks March 20, 2012 As the demand for enterprise collaboration continues to grow, more businesses are looking to internal social networks to manage workflow, foster collaboration and improve innovation.

5 Websites for Cool Facebook Cover Photos April 3, 2012 If you're looking to add a unique, personal touch to your Facebook Timeline, check out these sites for stock images, original designs and customized photo collages.

5 Hidden Gmail Tricks for Power Users May 8, 2012 How well do you know Gmail? Here are five tips, from setting up an automatic vacation response to signing out of your account remotely, that the average Gmail user might not know about.

12 Cool LinkedIn Features You Never Knew About May 15, 2012 There's a lot more to LinkedIn than just connecting with the people you know. Here's a look at 12 features, from a business card digitizer to a resume builder, that enhance your LinkedIn experience.

5 Google Calendar Tips and Tricks for Power Users June 7, 2012 Think you know everything Google Calendar has to offer? Here's a look at five little-known features to keep more you more productive and organized.

Google's Most Innovative Projects June 29, 2012 Google unveiled two new products yesterday at its I/O developer conference: the Nexus 7 tablet and Project Glass. Here's a look at how some of Google's other famous projects got their start.

How to Add a Cover Photo to Twitter September 18, 2012 Twitter announced several new features today, including new mobile versions and an updated profile page that features a header photo. Here's how you can upload one.

4 LinkedIn Tips to Help You Get Hired This Month December 3, 2012 Think you can't get hired in December? Think again. Here are four ways you can take advantage of the holiday season to hone your networking skills and land the perfect job.

Kristin Burnham covers consumer technology, social networking and enterprise collaboration for Follow Kristin on Twitter @kmburnham. Follow everything from on Twitter @CIOonline and on Facebook. Email Kristin at [email protected]

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