This is an interesting question. In order to see objects, we need light to hit our retinas at the back of our eyes. This sends signals to our brains, which process the information and produce an image in our "minds." However, when light gets too close to a black hole, it travels extremely slowly. This means that light coming from the area very near the black hole would travel to an observer far from the black hole very slowly.

So really, the answer to your question depends on which perspective we are observing from. For an observer at a great distance away from the black hole, the spectacle would be pretty boring -- we would eventually see the person (or preferably object!) be torn apart in slow motion. But from the perspective of the person or object going into the black hole, things would be happening at a "normal speed" and they would be torn apart almost instantly once they are close enough to the black hole.

First off, that depends on the size of the black hole. The smaller a black hole is, the more intense the tides are that it generates at the event horizon (the "surface"). For a black hole with the mass of a star, you would be torn apart and dead long before reaching the event horizon. Bigger black holes have their event horizons farther out relative to the strength of their gravity, so in a large enough black hole you might have to be well inside before you feel any tides.

If you are still alive to see it, there is nothing obvious that happens when you cross the event horizon. It looks like the event horizon - the black surface - is still below you, in fact. This is called the antihorizon. This is because space is moving away from you, toward the center of the black hole, at the speed of light, so anything on the far side of the antihorizon is invisible, just as anything on the far side of the event horizon would be if you were outside of the black hole. As you get closer to the center of the black hole, the antihorizon gets closer, but still always is below you; you never see what is happening at the very center of the hole (where all the mass is) until you get there.

What happens at the center of a black hole is an unanswered problem in physics. According to Einstein's theory of general relativity, which is currently the best description we have of the force of gravity (and, by extension, black holes), there is a point at the very center containing all of the mass, with zero volume, and where time itself actually comes to an end. This is called a singularity. However, the theory of quantum mechanics states that matter cannot be compressed into an infinitely small volume, no matter how infinitely powerful the force compressing the matter is. It is probable that Einstein's theory is wrong in that real black holes do not contain singularities, but what they do have in the center is a mystery: quantum mechanics has yet to come up with an explanation for gravity.

Say you headed toward a typical black hole feet first. The gravitational field near a black hole is very strong, and it gets stronger as you get closer to it. This means that the black hole would pull on your feet more than it would pull on your head. In fact, the difference between the force of gravity on your feet and the force of gravity on your head is so big that you would literally be torn apart. You wouldn't survive going into a black hole.

But let's assume you can build some sort of spaceship that will protect you as you head toward a black hole. What will happen? It depends on the type of the black hole. First, however, I should mention that all black holes do have something in common: they all have a closed surface called an event horizon. Once something, even light, is inside the event horizon, it can never get out.