As with any question like this, there will be a variety of answers. I can only stress that what you consider to be the most important in terms of both events and substantiation will be what counts the most. Take what is offered here as a potential guide and then reflect on what you consider to be the most important or essential events. For me, I think that Skeeter's initial approach to Abileen is important. It is what triggers most, if not all, of the events in the novel. Skeeter's approaching Abileen and forging the friendship with her helps to develop the essence of the novel's themes. I would say that the emergence of the resistance to racial integration through the buttressing of Southern segregation is also essential in the novel. The increase of resistance to change is what compels Southerners to embrace some of the worst in treatment of people of color, specifically African- Americans, as well as to ensure that the resistance in the women maids becomes a force to be acknowledged. If there is no resistance as a response to the growing injustice, many of the elements in the novel are not as evident. It is here where I say that the third most important element of the novel is the emergence of Hilly as the embodiment of Southern racism. Her work in the Junior League as well as influencing other White women to treat their help in the worst possible of manners is what prompts the conflicts that exist in the novel, and at the same time help to demonstrate the inherent barrier that makes the characterizations of the women fighting against injustice so poignant and powerful.