Citing your sources completely and correctly is an essential part of writing history, and planning ahead and taking care with your sources will save you from difficulty when you are finishing the final draft of your junior paper or senior thesis.
Careful citation will also help you avoid plagiarism. For more information, see "Academic Integrity at Princeton," which is available as a booklet and online through the Writing Center's Writing Resources.
Planning ahead and keeping track of what you've found will make it much easier to finish the final draft of your paper without undue suffering. Choose a way to keep track of the citations to all the books and articles you discover (in ascending order of technical complexity):
Many historians use "Chicago style," the citation style set out in the Chicago Manual of Style. But there are many other citation styles, so first consult your instructor or advisor about the preferred format.
For Chicago style, you should keep one of these references close at hand: