This is a book that developers should read because it helps you think about thinking, and is applicable to APIs and other software internals.
Warning: If you read this book you may find yourself distractedly aware of the UI faux pas circus that surrounds us (e.g. doors that have handles that look pull-able, but can only be pushed).
If this book can get even one designer to resist the urge to make screen UIs that look like glass bubbles or brushed metal the world will be a better place.
I also like Nigel Cross's stuff. His book Designerly Ways of Knowing (2006) is good but published in some absurdly expensive, for-libraries-only monograph series, so find it in a library rather than buying it. His more recent book, Design Thinking, is a collection of case studies with some analysis, a bit lighter but also good (and not $149: http://www.amazon.com/gp/product/1847886361/ref=as_li_ss_tl?...)
It is not a complete education on the topic, but it's a huge step forwards.
"Most people make the mistake of thinking design is what it looks like. People think it's this veneer -- that the designers are handed this box and told, 'Make it look good!' That's not what we think design is. It's not just what it looks like and feels like. Design is how it works."
If you want to learn about design, before reading books about colors, fonts, grid layouts or how to make an inner glow in Photoshop, you should start by reading something like Don Norman's "The Design of Everyday Things" to gain an appreciation for how things work, and why. Then worry about making them look good.