Electronic structure of materials, in particular transition metal oxides, has generated enormous research interest due to the fascinating array of electronic and magnetic properties they exhibit. These diverse properties primarily arise due to a competition between the localizing effects arising from strong electron-electron interactions with in the d states and the comparable hopping strengths driving the system towards delocalization. To achieve a microscopic understanding of these phenomena, it is necessary to investigate their electronic structures in detail. In this talk I will present the results of such investigations from some representative systems employing various photoemission and absorption spectroscopic techniques. I will discuss the results from some of the systems which are of current scientific and technological interest like topological insulators, magnetic surface alloys and FeAs superconductors moving on to the physics of transition metal oxides of the 4d family, ruthenates and 3d family, titanates and vanadates, which has always been a fertile research ground of condensed matter physicists.