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.
Regarding starting points in Portugal. On a trip (by car) down to Porto a few weeks ago, my wife and I stopped in Braga and really fell in love with it. It has a nice old town and cathedral.
Alternatively, on the border between Portugal and Spain there is an old fortress (La fortaleza) that has markets every weekend. From there it would be a 10 minute walk to Spain; it's just across the river.
Anyone with any ideas about a good starting point in Portugal?