Peaceable Projects Inc. is a U.S.-based non-profit group that brings the vast resources of the wide world together with the ongoing needs of the people who live, work, and travel on the Camino de Santiago pilgrim trail network in Spain.
2002 CF: 2004 from Paris: 2006 VF: 2007 CF: 2009 Aragones, Ingles, Finisterre: 2011 X 2 on CF: 2013 'Caracoles': 2014 CF and Ingles 'Caracoles":2015 Logrono-Burgos (Hospitalero San Anton): 2016 La Douay to Aosta/San Gimignano to Rome:
You need a copy of the Brian Sewell documentary "The Naked Pilgrim" which covers his journey by car through France and Spain to Santiago.
The route you will take after Poitiers is the Via Turonensis. Check the http://www.csj.org.uk website for the 'Paris Route' ( http://www.csj.org.uk/route-paris.htm )
In Spain you can buy an excellent map by Everest - Mapa turistico del Camino de Santiago that takes you from St Jean Pied de Port to Santiago.