What are some interesting points to study in the novel The Magician's Nephew?

While The Magician's Nephew is the
sixth book published as part of the Narnia Chronicles by C. S.
Lewis, it is actually the first in chronology for the series--a prequel, if you will, to
The Lion, the Witch, and the Wardrobe.  From your question, I can't
tell whether you've already read the book or if you're looking for some things to look
for as you read.  I'll try not to give away too many of the plot elements in case you
haven't read, but either way, this is a book full of interesting and symbolic issues to
think about and study. 

The Chronicles
are all allegorical in nature, so the primary element to look for in this novel is the
allegory--the characters and places which represent things greater than themselves. 
Consider the following:

• Aslan sings and creates
  a world--from nothing.


• Jadis, the ice queen, is an enemy
  to Aslan.


• Aslan and Jadis are locked in a battle between
  good and evil.


• Gardens and an apple and temptation are
  all part of this story.

One other important
thing to examine in this novel, especially if you're reading the entire
Chronicles, is all the "beginnings" in this novel which carry over
into the rest of the series.  And if you're looking for something more in-depth to study
and/or research, perhaps you could examine why this novel is out of chronological order
in the series.