In CMR manganites strong electronic correlations may be influenced and/or induced by electronphonon interaction (Jahn-Teller effect). As a result a unique interplay between spin, charge and lattice degrees of freedom causes a number of interesting and useful phenomena, like colossal (CMR) and tunneling (TMR) magnetoresistance, resistance switching and, finally, multiferroic behavior. The interfacial and polaronic aspect of all these effects, considering competing different electronic/structural phases, will be highlighted and some insights into a common “polaronic” origin of magneto- and electro-resistive properties will be discussed. For a prototypical phase separated CMR system, (La1-yPry)0.7Ca0.3MnO3, very large low-field CMR is due to exchange (AFM) coupling between ferromagnetic nanodomains, actuated by correlated polarons, which are located at the “intrinsic interfaces” between FM domains. Manganite/titanite superlattices (SL), e.g. [(La0.7Ca0.3MnO3)m./(BaTiO3)n]K (LCMO/BTO), are interesting as artificial multiferroic system, in which orbital, charge and spin reconstructions at the interfaces play an important role. SL’s have been grown by a metalorganic aerosol deposition technique on MgO(100) and SrTiO3 substrates. The structure of the LCMO/BTO interfaces was studied with atomic resolution by TEM and elemental chemical analysis (EELS). We show advantages of interface engineering to control magnetotransport and crystal structure of manganites. In addition a “layer-by-layer” growth of perovskite films is demonstrated.