The internal degrees of freedom of molecules and the variety of interactions between their quantum states give rise to rich energy level structure. Diatomic molecules, the system of choice in our studies, facilitate unique experiments that are not possible with atoms. In the presence of electromagnetic radiation, the energy levels of an atom or a molecule are “dressed” and experience shift and split into a doublet. This process can be used to exert control on molecules with light at the quantum level. In our work we combine high-resolution multiple resonance spectroscopy with the creation of dressed states in experiments aimed at control of molecular angular momentum orientation, the spin multiplicity of molecular states, and measurement of transition dipole moments. I will also discuss our planned spectroscopic studies of lanthanide dimers in relation to magnetism and quantum entanglement of spin ½ particles.