Here's a pretty poster of Sita, wife of Rama, who is kidnapped in the Diwali story by the evil Ravana. Print it for display or cut her out to use as a puppet, perhaps.
Here's a printable poster of a diya, the old-fashioned oil lamp used to light the way back home for Rama and Sita in the story of Diwali, and traditionally lit during the Hindu Festival of Lights to welcome the goddess Lakshmi into homes.
Here's a fun printable poster of the Hindu god of wisdom and success, Ganesha, also known as Lord Ganesh. Ganesha is the destroyer of evils, and is often seen riding a mouse.