My knowledge of Seattle is predominately about it's parks and schools.
The Ballard Locks is one of my favorite places here, and whenever friends or family visit for the day that's where I go. You can watch the Locks ebb and flow as the ships go through, and you can walk across to the other side of the canal. On one side is the neighborhood of Ballard
and on the other side is Discovery Park.
If you want a great view of Seattle that includes the Space Needle, go to Kerry Park on Queen Anne Hill.
Walking around Green Lake in the afternoon before the sunset is very popular. =]