Body Language in Interviews
Monster.com has a good article called Body Language Can Make or Break a Job Interview by Robert Ordona. Robert points out in detail how to enter, sit in the waiting area, shake hands, take notes, and even how to walk from room to room. This is a good comprehensive reminder of being conscious of how others are perceiving your non-verbal communication.
I would add that mirroring is often useful. If your interviewer is leaned back, legs crossed, looking relaxed, you don’t want to be sitting stiff-backed or leaning forward onto his or her desk. You don’t have to match the other person exactly, but adjusting your posture to approximate the other person will give them more of a feeling of comfort.
The advice on body language also works both ways: Interviewers should be conscious of how they come across in the same ways, because the candidate is sizing you up too!