A research plan is not appropriate for every research paper, but it will give you the elements of a plan that you can adapt to your project.
Scholarly research often begins with a literature review of published articles from law reviews and journals. The MHSL collection includes all all major law reviews and journals as well as many non-legal journals in a combination of online and print formats.
Law reviews are generally published by law schools and edited by students. They contain articles, essays and other commentaries on legal topics by professors, judges,attorneys and students. Law review articles often describe, from the writer's perspective, a current issue in the law, along with analysis of history and a proposal for change or resolution. They also contain extensive footnotes, with citations to primary and secondary authority related to the author's thesis.
You can find full text articles in HeinOnline (coverage goes back to first issue of most journals), Westlaw and Lexis Advance. You can find non-legal articles (for interdisciplinary topics) in the subscription databases found on the library homepage in the Databases A-Z list.
Once you find sources, you will need to keep them organized. Managing, organizing and citing references and sources can sometimes be a real challenge especially if you don't keep track of what and who you cite. There are many tools available to help you; ask your librarian or faculty advisor for advice on organizing research projects.