Social Media Examiner:http://www.socialmediaexaminer.com/
This site covers all things social and is a great resource for businesses trying to understand the social media landscape. Offers insights on how to create brand awareness, connect with customers, and increase sales through the use of social sites/tools like Facebook, Twitter, Google+ and LinkedIn. Check out the founder, Michael Stelzner on Google+, Twitter, and Facebook

Search Engine Land:http://searchengineland.com/
Great resource for all things search.

SEOmoz: http://www.seomoz.org/learn-seo
Great tutorials for SEO