What is the denouement (the ending) of "The Magician's Nephew"?

In addition to the wonderful tie-in of the apple leading to the wardrobe, there are a few other "explanations" for objects/situations in the other Narnia books. 

For example, when Jadis followed Diggory and Polly to the new Narnia, Jadis had grabbed the arm of a lamp post from England, and carried it with her.  When Aslan approached, singing Narnia into existence, she threw it at his head, but it merely glanced off and sank into the earth.  It then functioned much like a seed, growing a new lamp post which became the meeting place for Lucy and Sir Tumnus the Fawn in "The Lion, the Witch, and the Wardrobe."

Also, Diggory buries the rings (made by Uncle Andrew to take them to the Wood Between the Worlds) in a circle around the base of the apple tree in England.  In the last book, "The Last Battle," the Pevensies dig up the rings in order to get back to Narnia after seeing a vision during a dinner together with some of their oldest friends (like Diggory, who actually becomes the Professor who owns the house in "The Lion, the Witch, and the Wardrobe").

Basically, the denouement of "The Magician's Nephew" explains a good many things about "The Lion, the Witch, and the Wardrobe," as well as tying into other books in the series.