This article has some great/interesting thoughts on the interview process. It gets a little programmer-specific in the middle but stick with it as the best points are nestled inside including these points which I felt were most relevant:

"An important thing to remember about interviewing is this: it is much better to reject a good candidate than to accept a bad candidate."

"Good candidates will try to get more information out of you about the problem."

"always leave about 5 minutes a the end of the interview to sell [your company]"