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.
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 colourful Hanuman poster to print for Diwali. According to legend, Hanuman, the monkey king, helps Rama rescue Sita from the evil Ravana and defeat him in a mighty battle. Hanuman is worshipped as a symbol of strength, perseverance and devotion.