Any information that doesn’t fit within the framework of your outline, and doesn’t directly support your thesis statement, no matter how interesting, doesn’t belong in your research paper. Keep your focus narrow and avoid the kitchen sink approach. (You know, the one where you throw in every bit of interesting research you uncovered, including the fungal growth in the U-joint of your kitchen sink?) Everything you learn may be fascinating, but not all of it is going to be relevant to your paper.
An outline will help you organize your thoughts before you dig into the writing process. Once you’ve developed your thesis statement, think about the main points you’ll need to present to support that statement. Those main points are your sub-headings. Now, organize your thoughts and information under each sub-heading.
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.
An argumentative research paper takes a position on a contentious issue and argues for one point of view. The issue should be debatable with a logical counter argument.