Washington State Art Standards
SAM is the center for world-class visual arts in the Pacific Northwest. While the museum cost money the Olympic sculpture Park is open for all and both are walking distance from the ferry.
Frye Museum is located in Seattle, walking distance from the ferry for those who are willing for a good hike up the hill. It is always free and offers various studio classes.
Located on the University of Washington Campus, Burke combines art with history. I enjoyed the dinosaurs!
Has some great ideas in it's website. Also when it is open to the public it is ALWAYS FREE. A great place to visit and take your friends too.