Here's a colourful poster of Ravana to print for Diwali displays. According to legend, Ravana kidnapped Sita from her husband Rama to claim vengeance on Rama and his brother for having cut off the nose of his sister! In the end, Sita is rescued and Ravana is defeated by Rama, with the help of Hanuman. As you can see from the poster, Ravana has ten heads and twenty arms!
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.