Your child can learn a lot from this monumental epic if you emphasize on the right points when telling him the story.
Does your child know the tale of the Ramayana? If not, then make sure you let him know. Even if he is familiar with the legend, it is highly possible that he doesn't know it entirely, so try and narrate it to him bit by bit. Perhaps you could tell him a part of the story every night, before he goes to sleep. Your child can learn a lot from this monumental epic if you emphasize on the right points when telling him the story.
Brotherly love
Does your child have any siblings? If yes, then focus on the love the brothers had for each other. When you come to the part about Rama leaving for the forest on his exile, explain how Laxman too insisted on leaving the luxuries of the palace to live besides his beloved elder brother for 14 years. Similarly when Bharat learned of how his mother Kaikayee had banished Rama from Ayodhya, he was devastated. He immediately made plans to go to Rama and bring him back to rule. When Rama refused to return until his exile period was up, Bharat placed Rama's slippers on the throne and ruled Ayodhya in the name of Rama - keeping his place until he returned.
Similarly, when Soorpanakha was insulted by Laxman, she went to her brothers Khaara and Dooshan, who rushed to avenge her. They were, however, vanquished by Rama and Lakshman. She then sought Ravan's aid, setting the wheels for the grand battle between Rama and Ravan, good and evil, into motion.
In today's materialistic world where property disputes between siblings are commonplace, stories like these are needed to be told over and over again. You want your children to be by each other's side in times of need and to stand up for each other, and such deep affection doesn't just grow by spending time with each other. It grows when parents encourage such growth, and keep emphasizing the importance of love amongst siblings.
The value of a promise
Dashrath had granted Kaikayee two boons when she had saved his life on the battlefield. Now, many years later, Kaikayee demanded that her boons be granted to her. Her first desire was that Rama should be sent to the forest for fourteen years, and the second, that Bharat be crowned King. Dashrath was naturally heartbroken at the prospect of having to send his son into exile for fourteen years, and pleaded with Rama not to leave. However, Rama was determined that his father's promise should not be broken. Once a person gives his word that he would do something, he should do it. When Bharat begged Rama to return to Ayodhya, Rama once again said to Bharat that he could not be instrumental in breaking the promise his father had made to Kaikayee.
Love for parents
Rama's insistence on keeping the promise also shows the deep love Rama had for his parents. The fact that he willingly gave up 14 years of his life to exile to keep his father's word, shows his love for his parents. His love was such that he would willingly give up his life for his parents. Similarly, Dashrath too loved his child so deeply that when Rama left for the forest, Dashrath breathed his last.