Research on molecule-based-nanomagnets has progressed rapidly in recent years in materials known as single molecule magnets (SMMs), which exhibit a host of remarkable quantum phenomena. SMMs represent a molecular or 'bottom-up' approach to nanomagnetism, with advantages that include chemical control of molecular structure, spin, magnetic anisotropy as well as intra- and intermolecular magnetic interactions. They display properties of much larger ferromagnetic particles prepared by conventional lithographic methods but in a manner that enables fundamental physics studies. For example, quantum tunneling of the magnetization (QTM) has been clearly demonstrated and studied in these materials. This talk will present recent experiments that combine magnetization measurements with microwave spectroscopy to characterize the quantum superpositions states of "up" and "down" spin-projections that are at the heart of the quantum tunneling phenomena.