Too bad I didn't see this thread earlier. You'll be missing on a great ride in early May called the May Day Metric. Starts in Federal Way and has some challenging but beautiful routes near Mt Rainier.
http://www.maydaymetric.net/
I might have to dig up the maps from previous years and post it if you're interested in riding down here.
You should check out the tour guide from Bicycle paper for other events and rides
http://bicyclepaper.com/pdf/2010_NWTG.pdf