When you're first starting with artificial lighting, I think it's generally best to get comfortable with one light first, then move up to increasingly complex designs. This great and quick video will show you five different looks you can get from one light source.
Coming to you from Aputure, this helpful video will show you the versatility of one light. Note that while they created this tutorial with videographers in mind, the principles apply equally well to photography. In it, they're using a Light Dome with a grid to control the spill of the light. The Light Dome is similar to an octabox, except it has 16 sides ("Light Dome" was probably a better choice of name than "hexadecabox"). If you're new to artificial lighting, an octabox is a great modifier to start with. As the video mentions, you can get more versatility out of these five looks by using a bounce card or diffusion to control the shadows (also by varying the subject-to-light distance). Experiment first with the positioning of the light so you can get a good general idea of how the different locations create different looks, then fine-tune to your taste using diffusion and bounce cards or a reflector.