There are many tools for the garden and many ways to injure yourself with the tools.  Here is a comprehensive site about how to safely use many tools ranging from hand clippers to tractors:

The garden is a wonderful place for children to learn about nature and food production.  Excited and inexperienced hands can lead to injuries that can harm a child or cause an unpleasant experience in the garden.  The following references address garden safety for children.

  1. Getting ready for the garden
  2. Using tools and preventing injury