An easy way to develop your thesis is to make it into a question that your essay will answer. What is the primary question or hypothesis that you are going to go about proving in your paper? For example, your thesis question might be “how does cultural acceptance change the success of treatment for mental illness?” This can then determine what your thesis is - whatever your answer to the question is, is your thesis statement.
Take a trip to your local library or university library. Although it may seem old fashioned, libraries are chock full of helpful research materials from books to newspapers and magazines to journals. Don’t be afraid to ask the librarian for help either - they are trained in research and know where everything about your topic is located.
Although it may seem counter-intuitive, writing your introduction first may be more difficult to accomplish than starting with the meat of your paper. Starting by writing the main points (focusing on supporting your thesis) allows you to slightly change and manipulate your ideas and commentary.
Generally, speaking, there are two types of research paper: an argumentative research paper or an analytic research paper. Each requires a slightly different focus and writing style which should be identified prior to starting a rough draft.