Dictionary of Sephardic Surnames

For me, the most useful single resource for Sephardi genealogy is the Dictionary of Sephardic Surnames (Dicionário Sefaradi de Sobrenomes) by Guilherme Faiguenboim, Paulo Valadares, Anna Rosa Campagnano, published by Avoteynu. For those in the UK, there is a copy on the open shelves in the Asian reading room on the third floor of the British Library. Oddly the JGSGB library doesn't have a copy.

The authors have been through a large number of key sources. indexing references to specific surnames. A great time-saver.