This is debate for many on what classifies as 'black' magick, as some view it just causing harm to others, while others incorperate the control or manipulation of others in the 'black magick' sphere. Many as well do not view there are any such thing as neither black or white magick, as it is from the practitioner that ultimatly determines if the goal is 'good or bad'.
If you're talking about hexes, the best way to cast one is to create your own. There are several useful articles detailing on how to effctively write one, and a handleful of 'tried & true' hexes on the site as well, but it is usually better to write your own.
Other than that, there is a large scope of topics that could fall under the black magick umbrella, including necromancy, evocation, etc. Most of this is usually described as higher magick, which is something of a more ritualistic and advanced level. There are several books about those subjects if you're interested.
Keep in mind, that when casting hexes however, that many people believe that energy you put out into the world will eventually come back to you. Some believe in the three-fold rule, that the magick and energy you put out will be returned to you three-fold.