In drafting your social media policy you will have to ask, does your organization use social media? Is there an expectation or requirement that some of the employees will use social media during work hours? Do you want to encourage your staff and volunteers to engage in the use of social media either as a member service or as an advertisement or for something else? What are your goals with regard to social media and with your social media policy? Is there confidential information which needs to be protected? How are you addressing copyright issues? The answers will shape what direction your association's social media policy will take.
To my knowledge the most famous Social media policy currently is that of Coca-cola http://www.thecoca-colacompany.com/socialmedia/. Coke has a wide open policy, encourages its employees to use social media to essentially promote Coke and has made its policy available to the public. The Coke policy sets some guidelines or expectation for the use of social media. Coke encourages its employees to be “online spokespeople.” Your organization may want to be more or less like Coke.
My advice is that social media is not going away. Employees are using social media so you need to provide some guidance on when and how they may use social media while at work and what they may communicate in official association publications and personal communications concerning. Without talking to you I can't tell you what form your social media policy should take but I can tell you you need a policy. If you need assistance drafting a Social Media Policy (or any other policy) for your association or business please do not hesitate to contact me. firstname.lastname@example.org