Raymond Chen mentions Jason Moore's Usability on the cheap, Part 1. It's a great reading, especially for GUI guys like me.
However, I think the most important fact in the post is hidden in the second footnote:
Users being too busy is one of the basic rules of UI. Users aren't stupid, they aren't blind, they aren't incapable: they are just too busy to learn your UI. Humility is good for user experience.
BTW, this and Peter Provost's post about missing documentation reminded me in Joel Spolsky's User Interface Design foor Programmers, Chapter 6:
- Users don't have the manual, and if they did, they wouldn't read it.
- In fact, users can't read anything, and if they could, they wouldn't want to.
I really recommend that book.