Set the amount of hair strands. Use as little particles as possible, especially if you plan to use soft body animation later. But you need enough particles to have good control. For a "normal" haircut I found some thousand (very roughly 2000) particles to give enough control. You may need a lot more particles if you plan to cover a body with fur. Volume will be produced later with Children.
- Hair Length
Controls how long the hair are.
Emitter particles Emission panel