The Women's Agricultural Network of Vermont (which is a terrific resource in general) is teaching a course on using social marketing.  
"Using Facebook as a Marketing Tool for Farm Businesses."
It's the 24th of Feb and 24th of March. Online.
These two on-line sessions are designed for farm business owners and employees who are not yet using Facebook, or people who have just started to use social networking and want to make better use of them to promote their businesses. Topcis include: why use Facebook as a marketing tool; differences between personal profiles and business profiles; privacy considerations; setting up your account; how to engage with others; and methods to increase followers organically. To register, visit http://www.uvm.edu/wagn³ and click on the "Webinar & Learning Circle Registration" link in the green box on the right side of page. You will fill out a short on-line registration form, and then we will email you directions to participate in the series. If you have internet access and can hear sound through your computer, you will be able to participate, regardless of what kind of computer, operating system or browser you use. For more information, contact the Women's Agricultural Network by emailing [email protected] or calling 802-223-2389x15.