If yellow haired women are called blondes, and red haired redheads,
what do you call black-haired women?  A brunette is a woman with "dark
or brown hair".  So I guess I'm asking for the brunettest women
descriptor.

I don't think the English language has a specific word for a
black-haired woman. There's a Spanish term that is used in South
America, "morocha."

Raven haired.

Mmmm, raven-haired, that black so deep it seems to have blue in it.

I've heared jet and ebony used before...but that might be just from
too many Harlequin's...

I can't think of a 'common' usage one...perhaps because black hair
quite often a very dark brown, 'blonde' and 'brunette' encompasses a
range of colours (colors), black would be specifically only one colour
(color) or achromatic color for the nitpickers.

Is it also possible that this is a linguistic thing...can some of our
non english friends tell us if perhaps the Asian races for instance
have more common names for black hair and less for blonde? (Since
black hair is more prevelant).

raven it is

I meant to say, 
Raven it is, with 1.9 million google hits on that term (GRIN)

Results 1 - 10 of about 3,050,000 for black haired woman. (0.29 seconds)

Results 1 - 10 of about 676,000 for black-haired woman. (0.35 seconds)


Results 1 - 10 of about 1,840,000 for raven hair. (0.38 seconds)

OK, call your spouse "black haired" I'll continue to call mine "raven
haired" but she prefers someone with the sole of a poet (GRIN).

You could try "sable":

"The heraldic term for black"
home.kc.rr.com/gemstone/heraldry.html

"# an artist's brush made of sable hairs
# the expensive dark brown fur of the marten
# coal black: a very dark black
# a scarf (or trimming) made of sable
# marten of northern Asian forests having luxuriant dark brown fur
# of a dark somewhat brownish black"
wordnet.princeton.edu/perl/webwn

   (both from Google: define:sable

She might like the imagery better than Siliconsamurai's "raven", and
it would be just as poetic.  (The soft-furred little beasts have sharp
teeth and claws.)