The basic subjects and main topics covered by this book are: physics of black holes (classical and quantum); thermodynamics, entropy and internal dynamics; creation of particles and evaporation; mini black holes; quantum mechanics of black holes in curved space-time; the role of spin and torsion in the black hole physics; equilibrium geometry and membrane paradigm; black hole in string and superstring theory; strings, quantum gravity and black holes; the problem of singularity; astrophysics of black holes; observational evidence of black holes. The book reveals the connection between gravitational, quantum and statistical physics and also the importance of black hole behaviour in the very early universe. An important new point discussed concerns the introduction of spin in the physics of black holes, showing its central role when correctly put into the Einstein equations through the geometric concept of torsion, with the new concept of a time - temperature uncertainty relation, minimal time, minimal entropy, quantization of entropy and the connection of black hole with wormholes. Besides theoretical aspects, the reader will also find observational evidence for black holes in active galactic nuclei, in binary x-ray sources and in supernova remnants. The book should thus interest physicists, astronomers, and astrophysicists at different levels of their career who specialize in classical properties, quantum processes, statistical thermodynamics, numerical collapse, observational evidence, general relativity and other related problems.