My 8-year-old and I built a shelf for his room, based on the Rolling Cubby Bench plans. (The paint job is all him. He originally suggested trying to paint a picture of an eagle on it, we ultimately settled on a partial flag.)
I'm fairly new to woodworking, and this was my second of four projects I've built using plans from this site so far. Cutting and assembly was just a couple of hours, but finishing stretched this out into a several-night project.