am 4. Juni 2000
After much search for a book on Northern Spain. I believe this Cardogan guide to be one of the better ones. It does provide some essentials: overview and history of Spain's northern regions, culture, cuisine and travel highlights. Also good recommendations on where to stay and have a friendly drink with the locals.
A few drawbacks: lack of comprehensive maps of regions in relation to Spain as a country and more specific maps of towns that you may want to visit.
All in all this is the best guide I've found available to get you started and excited about your trip as well as help you focus your travels to a particular area in Northern Spain if time is a concern.