Thank you all for your wonderful suggestions regarding the gps, maps, compass and especially the Trip Advisor postings on Terra Di Nano.
I didn't have much to go on when I booked this location but thought it sounded beautiful and the propietor Giorgio was very prompt in his replies.
I have purchased a map called the Insight FlexiMap Tuscany (Flexi) [Map] by American Map Corporation before I received your posts.
I will be putting in my order for a Michelin map but am debating whether I should order a general Italy map or get another Tuscany Michelin map.
I will check with our rental company regarding the GPS as I hate to buy one when I have a built in one in my car at home. I will however make sure we pack a compass as I imagine the roads are not well marked once we get off the beaten path.
Safe journeys to all.
DiDi