Well I am not going to give you an analysis of all the characters - that is something you need to work out for yourself as you carefully read the book and consider each character's actions and their motives and their relationships with other characters. However, I will give you a few pointers to get you started. One of the aspects about characters you will want to consider in this novel is that they are seen not only through the eyes of the omniscient narrator, but also through the eyes of other characters, which sheds further light on them.
Ezuelu is the main character of this novel and is the chief priest of his tribe. He is singleminded in all he does and his held responsible by some members of his tribe for the increasing isolation of his people, exacerbated by the continuing advances made by colonialism.
Winterbottom is the English colonial officer in this region who clearly displays greater common sense and a higher level of sensibility than Ezuelu. He clearly believes whole-heartedly in the colonial enterprise and is an idealist.
You will want to consider to the characters of Clarke and other colonial officers, and the four sons of Ezuelu and how they compare and contrast with each other, in particular regarding attitudes to the colonial enterprise and how their tribal life is changing and being forced to change.