The all-knowing Wikipedia defines social media as "Internet-based tools for sharing and discussing information among human beings." But really, social media is about connecting, interacting, and sharing online.
From a promotional and marketing perspective, things are not so clear cut or easy. The biggest problem is that some people think of social media as just one more channel to push sales. You can but you have to do it gently and with your customers interests first. This is not a position for an intern.
The best way to get your head around website optimization is to open a Google analytics (free) account and check out the bounce rate of your site visitors. You can even run multiple experiments simultaneously. To Learn more about website optimization, check out google, Think 2010.
Web content development covers more than just writing compelling copy on pages. Things like link names, title tags, page titles, alt tags, task names, meta data, image names and descriptions, and call-to-action buttons all have to work together for a site to be usable and effective. Text should be concise and informative. For more details, see the .pdf file below.