The thesis statement is a 1-2 sentence statement at the beginning of your paper that states the main goal or argument of your paper. Although you can alter the wording of your thesis statement for the final draft later, coming up with the main goal of your essay must be done in the beginning. All of your body paragraphs and information will revolve around your thesis, so make sure that you are clear on what your thesis is.
A research paper is an expanded essay that presents your own interpretation or evaluation or argument. When you write an essay, you use everything that you personally know and have thought about a subject. When you write a research paper you build upon what you know about the subject and make a deliberate attempt to find out what experts know. A research paper involves surveying a field of knowledge in order to find the best possible information in that field. And that survey can be orderly and focused, if you know how to approach it. Do not worry--you would not get lost in a sea of sources.
When you outline your main ideas, putting them in a specific order is important. Place your strongest points at the beginning and end of your essay, with more mediocre points placed in the middle or near the end of your essay.
If you are writing a research paper for a class, consider the other students. Is it likely that they will also be writing about your topic? How can you keep your paper unique and interesting if everyone is writing about the same thing?