They are taller than ferais and shorter than orcs.
They are of average build, and have fine hair. Their ears are rounded, not pointed, and usually have separate lobes. They're pretty much like offworld humans in most physical respects, but don't assume that their biology, disease susceptibility and so on will be the same.
Human skin is pinkish ranging to rich brown (varying with area of origin, as with ferais, trolls and goblins). Hair ranges from blond to dark brown or from russet to brown. Eyes can be anything from orange to brown, green to brown, blue or grey.
Humans are known for being the most sexually promiscuous of the five races and (like ferais) intuitive and artistic. (Note that though this is the common perception, it is a generalisation and is not true in all cases.)
Magical ability is reasonably common in humans, and they are the most likely of the five races to have telepathy (though this is still very rare).