Obtain a computer with sound facility, and access to the internet. Absorb information about Harlem and the Harlem Renaissance by reading and watching online documentaries about the movement, while making notes. Write a first draft of your thesis, beginning with an introduction and thesis statement, in which you state your intentions with respect to the rest of the thesis. Ensure your thesis statement is one of intent, and not merely of fact, and one expressed in the third rather than the first person, so as to remain objective.
Write the main body of the work, considering the deeper implications of the Harlem Renaissance in the light of Black History and why it might have taken place, including when and why African Americans were first drawn to Harlem, the results of their having settled there in terms of the area's development and growth, and how the Harlem Renaissance impacted America with regard to politics, literature, music and the arts in general, and vice versa.
Expand on themes you have already outlined, such as biographies of some of the key figures of the Harlem Renaissance and what part they played therein, why the movement ended, and whether you think it has any continuing relevance for contemporary Americans. While writing your final draft, bear in mind potential arguments that might be presented against it. Finally, prune all superfluous words and passages, and ensure there are no grammatical errors.