Yeah, I agree with Tim on the way disc golf seems to be organized in the Seattle area. If you want the insider lowdown on what's goin' on then check out:
That site is the best source of current info on the Seattle disc golf scene.
If you plan on playing any of the local courses solo then it is a real good idea to have a map with you.
The "big four" (Lakewood, Seatac, Terrace Creek, and North Park)) Seattle disc golf courses are all poorly marked and not intuitive at all!
If you want to play some of the outlying courses then be advised that Riverview in Sumner and the course in Steillacoom are infamous for their multiple tee/multiple pin madness.
White River in Auburn is probably one of the easiest courses for a first time player to navigate. It's a nice woodsy course too.
The ultimate thick big evergreen tree PNW course is NAD park in Bremerton (and you get to take a ferry ride to get there!).
Crystal Mountain is about two hours from downtown Seattle but it is a very cool ski area type course.
Good reviews on all these courses at:
http://www.dgcoursereview.com/browse.ph ... &country=1