National Road Maps / Atlases:
Road Atlases that show Portugal on its own, rather than as a part of Spain, are rare. The best we have found are published by Turinta.
Central Portugal (Beiras / Serra da Estrela):
The best road map for the Central Portugal region we have found is the ‘GPS friendly’ 1:250.000 Beiras/Serra da Estela road map published by Turinta: