I. Ways to read body language. II. Reasons why you may have a bad memory. III. For me since I am a newbie in studying this subject hahaha!
Orientation of the body (or parts of it) is an excellent way to see where one's interests lie or what he wishes to avoid.
Legs are a good starting point because they are honest, if we want to go somewhere we'll usually point there - with our feet.
Attention and rapport (or lack of them) are easily spotted by signals such as:
I. Head movements - nodding and tilting are obviously good signs! (But be sure that they're not rather a symptom of impatience with a fast nodding).
II. Resting the chin in the hand is also an attention signal, but it's very passive and usually means that whoever's listening - isn't very taken by the words.
III. Leaning in or out - a very honest signal on the level of involvement.