This book focuses on several major, open questions in the theory of anomalous metals with correlated electrons, complementing theoretical advances with the latest experimental results on related materials, all presented by leaders in the field. The main emphasis is on the physics of cuprates and high temperature superconductors, charge- and spin-ordering and fluctuations, manganites and colossal magnetoresistance, low-dimensional systems and transport, Mott-Hubbard transition and infinite dimensional systems, and the quantum Hall effect.