  I discuss the no hair principle, the recently found hairy solutions, generic
properties of nonvacuum spherical static black holes, and the new no scalar
hair theorems. I go into the generic phenomenon of superradiance, first uniform
linear motion superradiance, then Kerr black hole superradiance, and finally
general rotational superradiance and its possible applications in the
laboratory. I show that the horizon area of a nearly stationary black hole can
be regarded as an adiabatic invariant. This invariance suggests that quantum
horizon area is quantized in multiples of a basic unit. Consideration of the
quantum version of the Christodoulou reversible processes provides support for
this idea. Horizon area quantization dictates a definite discrete black hole
mass spectrum, so that Hawking's semiclassical spectrum is predicted to be
replaced by a spectrum of nearly uniformly spaced lines whose envelope is
roughly Planckian. Line natural broadening seems not enough to wash out the
lines. To check on the possibility of line splitting, I present a simple
algebra involving, among other operators, the black hole observables. Under
simple assumptions it also leads to the uniformly spaced area spectrum.
