If you plan to hire a professional genealogist or conduct genealogical research by yourself, you will have to contact the elders in the family. Remember the first step:
Then you will have to find some information at home, and also from your relatives that may have kept old documents. The following documents are useful for the genealogical investigation.
Family Tree and Family Histories (unfortunately these documents are rare and most families do not have them)
Birth, marriage, or death certificates
Family Books: Known as “Libro de familia” in Spain, they have different names in Latin America like “Libreta de Matrimonio”
ID Cards: Driver licenses in the United States. That will be for the Spanish citizens “D.N.I (Documento Nacional de Identidad)” for recent generations and “Cedulas Personales” for the ancestors starting the late XIX century. In Latin America they are called “Cedula de Identidad”.
School records and Professional Certifications
Baby books and birth announcements
Military records (Cartillas militares)
Legal papers, deeds, wills. For the ancestors that did not make a will, the notary document for the distribution of the inheritance (División de Herencias).
Communion or Funeral cards (estampitas religiosas)
Emigration and Naturalization documents (only in the Americas)
Family bibles (mostly in North America)
All documents are important, even diaries, journals, personal letters, and postcards can give us a key piece of information. Just to give you an example I was researching one of my wife’s ancestors, an immigrant from Italy. I found a wall and was unable to find any information about this person until we discovered an old document that mentioned his ancestral city (Paola, Cosenza). With that little piece of information we were able to document 5 generations for this ancestor until the early 1700s.