A black hole is not actually a "hole" but was once a star that has collapsed in itself because it has exhausted its fuel supply, no longer being able to sustain its size. It's size is proportional to the amount of radiating energy that the nuclear reactions within it produce in relation to its overall mass, which is the source of its gravity. Since the mass (gravity)does not diminish as its energy does, its own gravity compresses it continually inward until it reaches a point called singularity- or infinate density. At this point gravity is so pronounced (strong) that not even light escapes its pull, hence the name black hole. It creates a region in space where all matter within the range of its gravitational field(event horizon) and light are pulled into it and compressed into singularity.
Under these conditions, it would never be possible for a human to survive being sucked into a black hole, as the closer one gets, the greater the gravitational pull. The theory of what would happen, is called spaghettification.The gravty increase in strength the closer you get to the center or singularity, and therefore acts proportionately on whatever foreign matter is being sucked into it. Say your floating torwards the event horizon feet first. Once you enter the event horizon, the gravity increases bit by bit in relation to the closest matter to the black hole. In effect, since the closest matter would be the molecules or atoms in your feet, they would be sucked in with increasingly greater force and speed than the matter furthest away-the top of your head. You would be stretched and stretched and stretched as you went deeper into the ever increasing gravitational vacuum. In essence, you would be turned into spaghetti.
Black holes are always increasing in mass, as they suck in the matter Aound them(other stars, astroids, planets,whatever) and therefore always increasing in weight and strength. They are in effect, galactic parasites, with a 100% mortality rate of their victims. If a person wants to become one with the universe, black holes are the ticket.