Skate Journeys offers inline skating lessons from brand new beginners to advanced skills. They have a number of instructors, all of whom are genuinely interested in teaching the students. They have kids classes, but most of the students are adults. The beginner class covers all the basics - striding, stopping, turning, falling...more advanced skills classes include trails, dancing, hills, etc. Very fun. If you're new to the sport and don't have your own gear, they will lend you everything you need (skates, pads and helmet) for your first 4 lessons gratis. Check out their website for info: http://skatejourneys.com/
Note: A lot of the lessons are at Skate King in Bellevue which is hard to find - it's in the back of a stripmall and isn't on the sign.