This page
http://www.loc.gov/nls/other/sayhow.htmldoes not seem to have been mentioned in the NG (according to Mr Google, at least).
A valuable tool, since, in many cases, the pronunciation is not that which an educated Briton (at least) would use in pronouncing the name of a citizen of the appropriate Old Country.
For instance, if told Katrina vanden Heuvel was a Dutch woman, I would (rightly or wrongly) pronounce her surname 'hoyv'l' (I don't speak Dutch!).
But, according to the LOC page, the surname of the 'Nation''s Katrina vanden Heuvel is pronounced
'VAN-dðn-hyoov-ðl'
A pronunciation that I suspect a monolingual Dutchman would not easily recognise.
Unfortunately, the LOC list is far from exhaustive when it comes to difficult surname pronunciations.
Reading about the Congressional travails of JFK, I come across the names of a couple of House members, Freylinghuisen (NJ) and Quié (LA).
Again, I'd be fairly confident pronouncing those names as belonging to Europeans, as
'fray-ling-hoys'n' and
'kee-ay'
But not those names belonging to Americans.
There is also Brademas (IN) - I wouldn't like to guess the origin of the guy's name, let alone how it is pronounced as such!