There's a lot of information out there regarding cultural bias and
cultural affects of interracial marriage, but is there anywhere where
Interracial marriage is discussed from a Sexual Selection point of
view?  For example what sex of what race would be attracted to what
sex of what race, and where can good data be found?  Furthermore, what
are the genetic reasons for these choices?

Hi,
maybe a comment will incite interest from someone who knows more about
this somewhat ticklish question, political correctness and all that.
Starting with your last line, Scrony, I think we would have heard if
anyone even thought they knew "genetic reasons for these choices,"
just as I think we would have, if someone thought they had found a
gene that causes homosexuality, which is also what you are asking
about:  "what sex ...attracted to what sex ...?"
(There was a question by Caucasian homosexual asking why he was
attracted to black homosexuals which you might find interesting.)
And I do not believe that anyone has yet suggested that a gene for
race has been found, but I expect that would (also) be a real PC
matter, and whoever would be extremely careful that he or she could
prove it before calling a press conference.

Maybe someone would like to comment on this.  

And maybe I am all wrong, but then you'd be a little further.

That puts the question for now back in the cultural frame (where I
think it belongs).
Certainly some cultures have been and are more open towards
homosexuality  - or homosexual activities  - ancient Greece for one -
and others  - like Islam - are extremely opposed.  But since it
nonetheless exists in almost exclusively Islamic areas, it would seem
that that culture is not responsible, can't suppress it.

Interracial sexual selection (either way) seems very much subject to culture -
and availability.  If there are no members of your (not personally
meant) race of the opposite sex available, you look at what is
available  - and you are probably in a situation in which your culture
is weakly represented, e.g., the crew of the Bounty in the South
Pacific or men in the Americas in the 16th and 17th centuries.  Of
course, Polynesian women  - and men - are attractive by European
standards, but if you have ever spent even a week or two in a country
of another race, you develop an appreciation of the physical features
of the people that you didn't have when you first arrived.
It is claimed that the Europeans who colonized S. America were more
open to interracial "marriages" than those who settled N. America.  If
this is true, then there must have been a cultural influence, but
culture changes, adapts.
100 years ago, Northern Europeans had attitudes towards swarthy
Southern Europeans that came close to seeing them as another race.

So where does that take us?  Not to an answer to your question,
especially as you narrowed it down to genetics.

scronyjameson,

You'll find a huge amount of information by doing a Google search
using the terms "exogamy" and "race/racial":

://www.google.com/search?hl=en&q=exogamy+race+OR+racial

Unfortunately, some of the sites which discuss this subject are
bigoted in the extreme. Racist hate groups maintain websites which, at
first glance, appear to contain scientific information. Be cautious.

With respect to myoarin-ga's comment. There is a gene (fruitless) in
Drosophila, which is responsible for sexual "orientation" See:

http://flybase.bio.indiana.edu/allied-data/lk/interactive-fly/dbzhnsky/frutles1.htm

Regarding the original question. You may want to look at some of
Roughgarden's work (she's a Stanford). Her data suggest that a genetic
basis for sexual selection (ie what fitness a peahen gains by
preference for peacocks with large tails) does not exist. Her work
also addresses "homosexual" relationships in the animal kingdom.

About the homosexual selection, if homosexuality was an inherited
trait it would most likely have become extinct by now as two
homosexuals cannot produce offspring to carry on the trait. 
Homosexuals throughout history have produced offspring with
heterosexuals which could possibly sustain the trait if it were in
fact genetic.  From a purely *evolutionary* viewpoint I would think it
would be disadvantageous for a homosexual to marry/mate with another
homosexual because they could not pass on either one of their genes to
the next generation.  Obviously personal happiness is more important
than capability to produce offspring and this supercedes the
disadvantage to not being able to produce one's own children.  Now
that people can have fertility treatments or adopt to take the place
of natural offspring that selection pressure is eliminated.

As for racial selection i think it is a cultural thing.   It seems to
be more of a vanity issue instead of a logical one.  There is no
benefit to the individual for choosing a mate of a certain color aside
from cultural approval or disapproval.  Unless you can make broad
generalizations about races.  Blacks are more prone to certain
diseases (as are whites, asians and everybody else) and that may put
pressure on somebody who wanted a "healthier" mate.  But the
differences between the races in health/longevity are so similar it is
unlikely to influence sexual selection.

Blacks are more likely to have diabetes and high blood pressure. 
Whites (almost exclusively)  are more prone to losing sharp vision
during older age due to Macular Degeneration.  People would have to
know the statistics for certain diseases for the races to make a mate
selection based on that.  Genetic reasons:  longevity, more offspring,
healthier offspring, lower expenditures during the lifetime to take
care of these matters.