According to the most 'scientific' sources I've seen, there are only a few races
per se:
Caucasoid (inc. part of Middle East, Northern Africa, scattered all the way into India and Mongolia, also inc. Ethiopians (hybrid w/ Negrids but closer to Caucasoid) and Ainu Japanese)
Negrid (sub-Saharan Africans)
Australapid (Australian natives)
Mongolid (East Asians and Pacific Islanders... and Native Americans are grouped here too)
Everything else is either a hybrid or a subrace. One source that I found just now to refresh my memory has the following subraces of the Caucasoid race:
-Europid (further splits into Nordid (northern European) and Alpinid (middle Europe into Poland and Ukraine)
-Mediterranid (inc. 2 groups: Spain, Italy, Greece, S. France; and Orientalid (Arab / Middle Eastern))
-Ainu (Japan)
-Turanid (central Asia from the Caspian Sea to Mongolia -- a hybrid between Caucasoids and Mongolids)
-Aethiopid (Ethiopia and Somalia (hybrid with Negrids))
-Sanskrit (India, Pakistan, Afganistan, etc.)
Of course these are probably still up for debate somewhat, but I do remember reading about the distinctions between the subraces. Like prevalence of eye and hair colors (e.g. blonde/blue obviously highest among Nordid subrace), the general shape of the skull (very tall and narrow for Nordids and somewhat rounder for Alpinids), and various subtle things in the nose.
I remember hearing somewhere that modern African Americans have, on the average, 25% European blood... there are many so-called 'Blacks' in America who really look more White than Black (Halle Berry being a prominent example -- she is at least 1/2 white) but are still called (and call themselves) African American. *shrug*
Hispanicity is officially treated by the U.S. government, as it should be, as an
ethnicity, not a
race. One can be nearly 100% African blood and have a Spanish last name and speak Spanish, and still be Hispanic. One can be 100% White and do the same. There are even some Asian Hispanics (like the guy who I think was pres. of Argentina or something? I forget). So on the 2000 Census, there were two questions: one for Race and one for Hispanicity. People are first asked "Do you consider yourself Hispanic or Latino?" and THEN they're asked what Race they consider themselves (and Hispanic is NOT an option). However, while technically correct, this causes a problem as many Hispanics in the U.S. are racial hybrids (Native Americans mixed with Europeans and Africans) and therefore have no real racial identity.... only their ethnic identity. I work for a Survey organization, and on our national surveys we ask the question the same way that the Census bureau does. And every time, almost all of the "Others" are those who also identify themselves as Hispanics, and if there's a place to specify what they mean by "Other", they almost always respond "Hispanic" or "Latino".
So, to the topic

.... I think that Jewishness is as much an Ethnicity as Hispanicity (sorry if these nominalizations seem awkward, but they're the best I could come up with). If you have one parent or grandparent who is/was 'Hispanic', then you are too, regardless of whether you're actually White, Black, Asian, or whatever. The same thing with Jewishness (although the rules are somewhat stricter... being Jewish is passed maternally).
So it's really like you're looking at two orthogonal things. Race and Ethnicity.