Local tour guides in Zaragoza, San Sebastian, Bilbao, Burgos ...

As we are with a group of friends going on a non-regimented tour, I would like to be flexible therefore can't book ahead with a company. It would be great to have the mobile number of a local tour guide I can contact during the course ... know any local tour guides I can initially contact by email for the cities of: Zaragoza, Pamplona, San Sebastian, Bilbao, Burgos, Segovia, Madrid? We will have our own vehicle with driver so the we can either do Posted in the Europe forum.