Phil Plait of Bad Astronomy states that if a person were to approach a black hole feet-first, it would pull his feet at a faster and stronger rate than it would pull his head. This essentially means that the person's body would be stretched into a long, thin strand until it was eventually fragmented.
Astronomers use a term called "spaghettification" to describe the effect that the aggressive gravitational pull of a black hole would have on a human being if he were to find himself close enough. The difference between the gravitational pull of two sides of an object is called the tidal force, and it causes gas-giant moons to break apart if they are too close to the planet. A black hole's gravity is powerful enough to break apart much smaller objects, such as a person, in the same way.
Black holes distort the fabric of space. They occur when a dying star finally collapses after a protracted and sequenced death. Stars naturally spin, and their spin speeds up rather than stops as they collapse into black holes. Phil Plait states that this rotation causes the nearby space to spin faster than light, and this continues until the black hole evaporates. Scientists are still unsure of exactly how black holes work.