In the last years, after the discovery of molecular nanomagnets showing novel quantum effects, a renewed interest for the study of molecular magnetism and multifunctional molecular materials has emerged. These materials have triggered an intense research activity also in view of their possible applicabilities as, for example, as nanosized information storage units and as magnetic nanoparticles for bio-medicine. Several fundamental aspects of the microscopic static and dynamic properties of these molecular materials have been obtained by means of spectroscopies using local probes, as nuclei...