So, there's a real problem here with the question itself. A black hole is a thing that can't be seen, bit the effects of a black hole can be seen. So, if the question is "What does a black hole itself look like?" The answer is "nothing. It looks like the absolute and complete absence of all things." If, however, the question is "what would we see if we tried looking at a black hole from a reasonably close, but safe, distance?" It's a little more complicated. Mostly, you'd see a pair of rings at 90 degrees to each other made of the brightest stuff imaginable and separated in your view by areas of the blackest, darkest hemi-circles you can imagine, except the borders of both areas are really, really fuzzy.

Also: black holes, if they had dimensions, would be spheres, and their effects are also spherical (sort of...kinda ellipsoidical, depending on rate of rotation and such, but generally spherical)