The 88 volumes of the Diccionario Heraldico y Genealogico de Appellidos Españoles y
Americanos, library of congress call number CR2142.G3 contains some 15,000 Hispanic
surnames with a history of the surname, coat of arms, plus a bibliography for further
research. This is a gold mine.
Visit the library of congress online and perform a search of the index.
http://www.loc.gov/rr/hispanic/geneal/index_gc.html
Do not use accents when submitting a search, it confuses the search engine.
I just came accross this resource today.
Dani