You'll no doubt remember the great information Lisa Schroeder shared with us in December about life as a novelist. She posted last week about how Twitter helped her launch CHASING BROOKLYN. If you're still thinking about joining the fray, this will probably make you take the leap.
While you're getting started, you can find Lisa here: http://twitter.com/lisa_schroeder. And you can find the SCBWI Western Washington here: http://twitter.com/scbwiwwa.
Meanwhile, here's a piece by Harold Underdown (author of the Idiot's Guide to Children's Publishing) on social networking and online promotion, and what authors are expected to do these days.