The existence of the first truly two-dimensional crystal was demonstrated experimentally in 2004 when Geim and Novoselov managed to isolate Graphene. The remarkable properties of this material triggered a surge of interest for 2D materials and, in recent years, the number of discovered 2D materials has grown enormously. A family of layered materials that is attracting renewed attention in these years is the one of the Transition Metal Dichalcogenides (TMDs), which have been studied for decades in their bulk form and that recently have attracted considerable interest in their ultrathin (few and single layers) form. They present a wide range of electronic, optical, chemical and mechanical properties and some exhibit exotic behavior such as charge density waves or superconductivity. The investigation of superconductivity and of its properties on TMDs (and, in particular on MoS2 and WS2) constitute the main research topic of this thesis.