I would definately visit both Segovia and Salamanca on your way to Galicia. In Segovia I highly recommend the Hotel Infanta Isabel:
Infanta Isabel

It is right on the main square and we requested (and received) a wonderful room overlooking the square with a balcony and perfect view of the cathedral. I still have my little slippers that we received and everytime I wear them think of this lovely place.

There are lots of postings on hotels (and restaurants) in these cities, just do a search and you'll come up with lots of ideas.