I came across this site http://www.viadelaplataguide.net/ which has a free guide to the via de la Plata - I was able to put in straight on my Kindle and haven't had much of a look at it yet but every little helps when planning a Camino! Maps are available (in Spanish) at http://www.gronze.com/guia-via-plata/etapas/etapa-1-sevilla-guillena Image taken from https://www.caminodesantiago.me/is-via-de-la-plata-really-not-walkable-in-july/
A blog about the Pilgrimage to Santiago de Compostela