A Suggested Seven-part Model
Suggestions about approximate lengths are placed in brackets
The first suggestion is for a précis or a short paper  (1200 to 2500 words; 5-10 pages)
The second suggestion, after the pipe ("|"), is for a longer piece (5000 to 8000 words; 18-30 pages)

Alan Kimball

(1) Title and author (you), with date indicated. [Two or three lines]

(2) Explain what your topic is. [One paragraph | one page]

(3) Describe the main historical literature (the secondary sources [ID], including standard reference works [ID],) on your topic. What do other historians say about your topic? [Two or three paragraphs | three pages]

(4) In view of (3) above, what will you say either to amplify, augment, reinforce, reinterpret, correct and/or displace what we already know from the hitherto existing secondary sources? State your hypothesis, your particular reason for taking up this topic. [Two or three paragraphs | two pages]

(5) Main body of your essay: In a preliminary précis, you need only describe the main documentary material (the primary sources [ID]) on your topic. How will you later use these materials to achieve the objective stated in (4) above? In a shorter as well as a longer research paper, you will at this point actually use these primary sources in conjunction with secondary sources to achieve the objective stated in (4) above. This point (5) is the main bulk of a précis, short research report or longer "term paper" [One or two pages in a précis and three or four pages in a short research report | ten to twenty pages in a longer research paper]

(6) Notes, either footnotes, endnotes or inter-textual notes

(7) Bibliography [a sample in the précis | a fuller list in a short research paper or final "term paper". A full bibliography may include sources consulted, even if not cited in the narrative]

If you are not given specific instructions about the forms to follow at points (6) & (7) above, you are well guided by this UO KNIGHT Library page
You might also consult Kate L. Turabian, A Manual for Writers of Term Papers, Theses, and Dissertations.

Some Procedural Suggestions

I recommend you consider the following order of work: First, write a preliminary draft of (2); it is sometimes useful to return with some frequency to rewrite (2) as your work progresses. But after first draft of (2), move quickly to reading and thinking about (3). Keep separately organized notes on (5) and, all the while, keep good records for (7). As report time approaches, turn seriously to (4). Once you have satisfied yourself on (4), rewrite (2) and make final adjustments to (1) [that is to say, to date & title, not ordinarily to your name]. Put (6) and (7) in order and produce your text

Some final thoughts = Strive for maximum clarity. Consider the following two challenging propositions =

The second bulleted proposition, need I say, in no way presumes the impossibility of being right and being clear at the same time.

Whether a short exercise, like a précis, or a longer research paper, writing is difficult. To produce with maximum clarity, precision, and accuracy even a précis or a short paper in 5-8 pages (including 2-4 pages of notes and bibliography) is a real challenge. A longer final research paper is actually only a slightly greater challenge. In my experience, students often doubt that they could ever compose a 20-30 page "term paper", and then they find themselves at the end generating 30-40 pages. In both shorter and longer narratives, you have to be comprehensive without being verbose, so you will have to make choices about what to include (the most important information, always interlinked with your main arguments) and what to exclude (the less important, repetitive or irrelevant information). You will have to hone your narrative style to waste no words. I sometimes like to advise that papers always be as short as possible but long enough to get the job done, to satisfy the promises implied in the seven-part model presented here.