Recently ideas to engineer Majorana fermions in the solid state have been developed. These Majoranas, quasiparticles that are their own antiparticle, have received much attention, as they are expected to fulfill non-Abelian exchange statistics and could potentially function as fault-tolerant quantum bits. This thesis focuses on a Majorana host system consisting of a semiconductor nanowire with a strong spin-orbit interaction contacted by a superconductor placed in a magnetic field. The properties of the semiconductor nanowire relevant to the stability and controllability of Majorana devices, namely its spin-orbit strength and its disorder, are studied experimentally for the case of indium antimonide (InSb) nanowires. The synthesis and electrical properties of small networks of nanowires, needed to probe the exchange statistics of Majoranas, are also investigated. Besides a study of their potential for Majorana devices, these experiments also explore the mesoscopic physics in InSb nanowires.