This book contains a collection of texts ranging from a basic introduction to the mathematical theory of spin glasses to state-of-the-art reports on current research, written by leading experts in the field. It provides a unique single reference volume that will guide the novice into the field and present an overview of recent result to the experts. The subject matter covers mean field theory of spin glasses, short range spin glasses as well as other models of statistical mechanics in random media, such as polymers in disordered potentials. Besides equilibrium statistical mechanics, nonequilibrium properties such as ageing are addressed. The focus of the book is on mathematically rigorous aspects of these topics.The book is intended for graduate students and researchers.