Below is a link to a course from Dell Small Business 360. It's for three 20-minute on-demand webinars where you'll learn:
Lesson 1: Basics of Business Promotion and Relationship-Building on Social Networks
Lesson 2: Using Facebook, Twitter, MySpace, LinkedIn and Other Major Social Networks
Lesson 3: Examples of Effective Business Promotion on Social Networks
http://tinyurl.com/6gmsl7