APA format is used by researchers in the social sciences field, and requires in-text citations as well. It ends the paper with a “references” page, and may also have section headers between body paragraphs.
If you find one really awesome book or journal that fits your topic perfectly, try looking in the works cited/bibliography/reference list at the end of it. This should contain many more books and journals that are about your topic as well.
A single main point doesn’t have to be kept to a single paragraph, especially if you are writing a relatively long research paper. Main ideas can be spread out over as many paragraphs as you deem necessary.
The body of your essay will revolve around the ideas that you judge to be most important. Go through your research and annotations to determine what points are the most pivotal in your argument or presentation of information. What ideas can you write whole paragraphs about? Which ideas to you have plenty of firm facts and research to back with evidence? Write your main points down on paper, and then organize the related research under each.