I mentioned a paper by Bill Buxton in class yesterday
(1/29/08) when we were talking about user interface design. It talks about some of the problems with current research in human-computer interaction today. He illustrates it with some great examples of seminal interface work and how one can get to it (sometimes). The paper is at:
this link
I also mentioned "The Design of Everyday Things" by Donald Norman. It's got some terrific guidelines and best practices about how to make interfaces that are "intuitive" and "easy to use".