A colleague borrowed me this book on user interface design and human perception. I enjoyed the read so much I hustled out to Amazon to buy my own copy.
Jeff Johnson does a terrific job of precisely but concisely discussing various modes of human perception and cognitive processing, and simultaneously relating them to UI design practices or guidelines. Not a book that will tell you how to use CSS or XAML to lay out your controls, but a book that will help you decide which controls are important to have, what they should mean in the context, and how to avoid misusing them.
Not all the details he discusses are relevant to all domains, but overall this is a hugely enjoyable and accessible book!