Is there a list of all normal subgroups for $S_N$?
What is a criteria for a finite group to be a normal subgroup of $S_N$?
Which of them are kernels of irreducible representation? From a partition of $N$, we can construct an irreducible representation, so how does the related subgroup look in terms of the partition?
It is a standard fact in group theory that when $N\geq 5$, the only normal subgroup is $A_N$, which in turn is simple. For $N\leq 4$, you can just do it by hand. There
areis of course exactlytwoone irreducible representation whose kernel is $A_N$,the trivial andthe sign representation.I don't understand the last paragraph of your question, but there are lots of references on representations of symmetric groups, e.g. the representation theory book by Fulton and Harris.