Create a thesis statement, or take a stance on the topic. Research your topic to know what angle you want to emphasize. For example, if you want to write about the worldwide declines in fish populations, your thesis sentence might say something like, "Human activities are the primary cause of fish die-offs."
Find a couple of websites or authors who support the point of view you're going to be writing about. Make a pro-con list: Separate some research for and against your point of view. Make sure to include where you found the research, so you can return and reference it later.
Begin writing the research paper outline. In a word-processing program, and set up a format in Roman numerals (or some sort of bulleted list). Write out your thesis sentence first. Under it, write the number "I" and begin creating individual points to support the thesis. Keep things as organized as possible. Use capital letters for major points, and write any notes you have in the margins.
Write points II, III and IV under the number I. Leave a lot of space between numbers. You may need more numbers depending on the length of your research paper, but for the outline, start with just four. These points will be the support for your research paper. With the example of declining fish populations, your paper might list pollution and overfishing as the first two points. Decide if you want your points to be phrases (for a topic outline) or sentences. List one reason for support for each number.
Make sub-points under these numbers and list interesting facts or supporting evidence for that sub-point. You might label these with capital letters such as "A." and "B." For each fact or piece of evidence, describe or elaborate upon your reason for support. So if you were writing on the sub-point for "Pollution," you might write, "United Nations research on urban runoff."
Consider adding points under sub-points if you want to be more detailed. You can label this information with Arabic numerals, such as "1." and "2."
Look for information opposing your thesis to begin point IV. Cite research that doesn't agree with your thesis and then write about flaws in that research, or address why it might be misleading.