I think the best guide to a Camino, any Camino, or any journey abroad is not to have a guide book but just to know where you want to go and trust, en route, to luck, chance encounters and fate.
You will learn more from the people you meet and what they tell you about themselves or where you are than in any guidebook, which will, in any case, probably send you to sleep whilst you read about the dusty details of some local ancient building or church "This is an interesting architectural example of an interregnum castle which has references to the Mausoleum of Hadrian and in the church you will find of interest, in the clerestory of the west transept, knosps in the pendentive arches.... blah blah blah".
That local or or new acquaintance will tell you that the best meal in town with the most interesting people is that bar/restaurant just round the corner on the left.
If you are really desperate (and you would need to be desperate) to know about those knosps and pendentive arches - Google it when you get home.
No pilgrimage or journey abroad should be a "pre-packaged" or an overly planned journey.
It should be an adventure and a voyage of discovery.
Throw caution to the wind and let life throw at you what it will