How can I write a successful essay on Joyce Carol Oates's novel Wonderland?

One way you can write a successful essay on this novel is to look at how Oates's Wonderland parallels Lewis Carroll's novel Alice's Adventures in Wonderland because it is obvious Oates uses Carroll's novel as the framework for hers. Like Alice, Jesse finds new worlds and meets zany characters that parallel characters we find in Alice's Adventures in Wonderland, and like Alice, Jesse discovers worlds and characters that are out of proportion, where emotions, ideas, and appearance are all grossly exaggerated. 

Another way to approach an essay on this novel is to look at the themes that run through it. One theme that is predominant is that of identity. Jesse's identity is always in question and seems to hinge on whether or not he is involved in a meaningful pursuit. In addition, his last name changes frequently, and since so much of our identity is tied to what we are named or name ourselves, this is significant. Last, as a doctor, Jesse has the power to cure his patients, but he does not seem to be able to 'cure' himself. A diagnosis for what ails him is elusive. You can tie this to identity, as well.

Another theme is the idea of what shapes a life's path, personality or fate? In many ways, Jesse's life's path twists and turns in ways over which he has little, if any, control. But in other ways, it is his personality that leads him to make certain decisions, which in turn lead to consequences and circumstances he may have avoided were he to have made a different choice. 

Another approach you can take is to examine the novel to see if/how it meets (or not) the criteria to be called a Gothic novel. There are many who critique Oates's work through that lens. Most Gothic novels contain a number of similar characteristics, including a gloomy or decaying setting, many with secret passages, trapdoors, or other mysterious architectural features; a damsel in distress who is rescued by a romantic hero; romance; ancient curses or prophecies; and a supernatural element. 

A concise, focused thesis that makes a clear argument and solid research from credible sources will help you make the most of your argument. Good luck!