Like I said in the FotF thread, I think the most important difference between animals and animal men is that more communication features are transferred to the face. For example, ants communicate mainly with pheromones, bees with dancing and pheromones, dogs with their tails, scents, barking and pheromones, etc, while humans primarily use the face and voice with secondary (and often unintentional) communication from the stance, sweat (more pheromones
) and movement.
Additionally, natural defensive capabilities may be replaced or enhanced by taking advantage of better manual dexterity. Early humans for example used clubs which extend the reach and grant increased power for the same muscle mass, whereas our humanoid ancestors probably used their fists, claws or sticks as clubs.
So my guide to turning an animal into an animal man:
1. Give them the capability of erect posture - even if the preferred mode of movement is not erect
2. Increase in prominence the facial features, such as sensory organs and the mouth, stylise obfuscating fur/hair/feathers/scales
3. Add opposable digits to forelimbs
4. Body decorations such as tattoos, dyeing, piercings, clothing, jewelry and paint
5. A society which mimics the human equivalent of the animal's system (so caste/feudal society for ants, tribal for wolves, nomadic for deer, anarcho-communist for apes, etc)
These things should be followed to different degrees, and there is no reason that the enhancements should necessarily be recognisably human themselves. For example, antmen should have more prominent mandibles for which there is no real human equivalent, and birdmen should enhance the beak while their ears remain largely hidden.