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.
Spend time going over the assignment. Look at everything your instructor has provided you with. Carefully read the writing assignment, prompts, grading rubric, or any other materials you’ve received. It might even be helpful to highlight and take notes on the assignment.
A prospectus is a formal proposal of a research project developed to convince a reader (a professor or research committee, or later in life, a project coordinator, funding agency, or the like) that the research can be carried out and will yield worthwhile results.
If you want to find helpful and reliable sources of information, the library is literally the best place to look around. There are numerous books, published articles, journals and etc. that you can choose from about your chosen topic.
Once you understand what you’re being asked to write in your research paper, it’s time to decide what to write about.