It really depends on your goals from here. Are you looking to boost traffic from social sites? If so, you're going to want to learn what your audience wants and start creating it, sharing it and participating in conversations on these platforms to earn their trust and engagement.
If your goal is to provide customer service and reputation tracking/management, you can set up alerts through services like Google Alerts (www.google.com/alerts) and many other services (this Quora thread is quite helpful on tools that can assist on that front: http://www.quora.com/Are-there-any-free-tools-available-to-track-Twitter-mentions-and-ideally-sentiment)
If you're seeking to boost SEO rankings using social media, you'll need to build up an engaged contingent of friends/followers who will share/like/tweet your content.
Some good resources include:
- http://www.seomoz.org/blog/social-media-marketing-facebook-twitter-arent-enough
- http://www.seomoz.org/blog/comparing-seo-social-media-as-marketing-channels
- http://www.seomoz.org/blog/a-visual-tour-through-the-basics-of-social-media-marketing
Best of luck!
