Take a look at these resources to find the answers. These are great places to find the numbers and facts.
The (Professional) Social Media Site
Build a "web-presence resume" quickly and easily!
Sign up or Watch Linked In Webinars to get started!
Read "Why You Should Use LinkedIn More Than Facebook or Twitter."
Steven Chappell. “Why You Should Use LinkedIn More Than Facebook or Twitter." Prof KRG. profkrg.com, 19 March 2012. Web. 20 September 2012.
Find out where professionals from your career of interest gather. What are they excited about? What are they complaining about? What skills are they discussing? A few places to look are: