Speaking as a total ignoramus on UI design, I would also suggest reading everything and anything by Edward Tufte (the Visual Display of Quantitative Information might be a good start). It won't give you any special insights into UI, but it should help to reinforce the point that making a good UI isn't about dumbing things down (a common geek misconception), but having a very strong sense of respect for the user. Good luck! (And the Norman book that everyone recommends is also a great read)