1. Your Website
The definition of social media is any broad based publishing platform where groups of people share information. Your modern practice website should have this functionality. You and your key staff should be able to easily update and keep your website fresh. News, your newest cases, events and other time sensitive info should be posted on your website. Your website is the command and control center of your whole web strategy. If your website doesnt have this functionality dont bother doing other types of social media until it does. Unlike other social media channels you OWN your website and work you do on it has a lot of value. Your website is clearly the starting point for any discussion of social media.
Bottom Line: You need a content managed website that connects easily to social media channels