Photoshelter has written a rather large informative guide on social media for photographers, and how they can be used to promote the business and make sales.

I was interviewed on my usage of Twitter for the three aspects of the business - commissioned photography (@craig_photog), stock images (@ImagesofBrum), and black and white prints (@crowdedgallery).

A PDF of my interview can be seen here.  If you want the full social media guide, visit Photoshelter.