Well it's actually a hobby of my dad's. ...He helped me a little with building it, showing me how to use the various tools and basic cabinet construction... It definitely helped having the guidance of a skilled woodworker though.
For finishing, I sanded everything with progressively finer grit until everything was sanded with 220. No stain was used and yes, I used the polyurethane pictured, I just applied several coats to make sure everything was protected from water damage as much as possible. That's all there was to it.WOW! Very nice job and the first time I have seen anyone using dovetails in their cabinet construction.
I am assuming that no stain was used but you did seal with the Rustoleum Polyurethane pictured? Give us details on the finishing steps.