West Coast Armory's new range in Bellevue/Factoria is really nice, as is the Kenmore range if you are staying around the Eastside area. Avoid Wade's IMO.
In terms of shooting on private property in King County, they have very specific no-shooting zones established, and if you are in them, even on your land, my understanding is it is a pretty hefty fine.
Here is the King County doc - about a hundred pages in is the relevant section - 12.68.xx
And don't forget, different townships can pass a local ordanance.