These are the most important guides to the Road of Santiago. The Road to
Santiago is written by a Spanish, Jose Maria Anguita Jaen, Editorial
The Pilgrimage Road to Santiago and Camino de Santiago by David M.Gitlitz and Linda Kay Davidson, and by John Brierley. You can find it on Amazon.com.
The fourth one, El Camino de Santiago, is pusblished by El Pais, the most important Spanish newspaper. You can buy it only in Spain and we suggest to get it at your arrival.