Learning the basics of robotics is going to be much easier when you have the right tools. The LIME happens to be a robotic hand with a companion software (Lyoth) to teach you a thing or two about robots. The hand is powered by 3 servo motors, 5 fingers, and 5 pin connections. It is Arduino friendly.
The control software lets you test the robotic hand. It runs on Windows, Linux, and Mac. You can use your LIME to tackle more sophisticated projects or just get your child more familiar with robots. You can find this product on Kickstarter.