We give a brief historical introduction to the Vector Meson Dominance model, a possible description of the electromagnetic interaction of hadrons. Then we focus on baryon resonances: processes relevant to their electromagnetic interactions, and the construction of Effective Lagrangian models describing these processes. This will be followed by a discussion of the di-electron production process in pion-nucleon collisions, with an emphasis on what we can learn from angular momentum and polarization observables. We give the connection to recent and planned experiments by the HADES collaboration in GSI, Darmstadt.