Universal Principles of Design is, without a doubt, one the best design books I’ve ever purchased. Not only does it help with my web design work but it also helps me understand and correlate my research in systems development.
Even better, unlike most design books that are filled with tons of design examples but very little knowledge substance, this book explains exactly why things look and function well together. It is a book that I’ve already picked up numerous times and will continue to do as it’s an excellent reference.
If you’re a designer of any kind (i.e. application, web, graphic, product, etc), I guarantee you won’t be disappointed with this book, as it will help you overcome many critical design decisions that you might encounter. If you’re located in Vancouver, you can get it at Oscar’s Art Books (another place I highly recommend as well).