Mounting or standing above another dog by putting front paws on the other dog's back means asserting dominance. It isn't just a male characteristics for females do it too. Mounting is more often related to social status than to sex.
Licking the lips is a sign that a dog is worried or is trying to appease a person or another dog. A relaxed mouth means a dog is calm. Lips pulled back is a challenging or warning sign, especially when combined with a snarl.
Direct eye contact means that a dog is feeling bold and confident. Casual eye contact means he's contented. An averted gaze means indifference. Dilated pupils indicate fear.
Relaxed ears mean that a dog is calm. Erect ears show that a dog is alert and attentive. Ears that are up and forward mean a dog is challenging or being assertive or aggressive. Ears that are laid back indicate that a dog is worried or scared.
A relaxed tail means that a dog is calm and at peace. A tail head straight out, wagging rhythmically and slowly, means that a dog is cautious or on guard. Tail down indicates worry or uncertainty.