Whitney's got a great sense of community and really does her homework when writing. She interviewed me and a bunch of other designers to put together an article on process vs portfolio.
The book I've been referencing lately to programmers and just non-designers in general is The Non-Designer's Design Book by Robin Williams. It's an overview of the concepts of c.r.a.p. - contrast, repetition, alignment and proximity.
http://37signals.com/svn/posts/1952-i-gave-a-talk-on-ui-fund...