The volume contains the lectures delivered at the XIII Training Course in the Physics of Strongly Correlated Systems, held in Vietri sul Mare (Salerno) Italy, in October 2008. The project of the meeting was to promote the formation of young scientists by means of training through research. These features are reflected in the book: the lectures are up-to-date monographies of relevant subjects in the field of Condensed Matter Physics. Contributions include: Quantum Magnetism in insulators (Single impurities in semiconductors and insulators; One- Two- and Three-dimensional magnets and quantum phase transitions; Undoped and doped Kondo insulators); Novel quantum condensates in excitonic matter (The physical systems: excitonic insulators, the Dicke model, exciton and polariton BEC; Second quantization, coherent states and path integral; exciton and polariton condensates in mean field theory; Open systems and Keldysh formulation; Phase-breaking and open system dynamics); Introduction to unconventional superconductivity (Generalized BCS theory; Phenomenological approach and symmetry aspects; Generalized Ginzburg-Landau theory; Josephson and tunneling effects); Quantum Monte-Carlo simulations (Classical and quantum cluster algorithms; The worm algorithm; Optimized ensembles for classical and quantum Monte-Carlo simulations; Continuous time QMC solvers for quantum impurity problems and DMFT).