On The BrandBuilder Blog, Oliver Blanchard gives a great overview of and insight into Best Practices for Social Media: The Basics of Program Planning.
Included in this overview is a description of the four components of any social media program, and briefly covers each. According to Blanchard, those are Development, integration, management and measurement. This is important to point out because it lays the foundations for structure and the assignment of specific roles within the context of Social Media.
Blanchard goes into more detail about the four roles, and their purpose as building blocks in a well-structured social media program. It is written mainly for the enterprise space, but the ideas he presents can easily be applied in any number of settings.
Take the time to give it a read.