There is no "one-size-fits-all" approach to legal research, but the steps below should be effective for most legal research issues. Depending on your situation and the amount of information available, you may start in the middle of the process, omit some steps, or even repeat others. Continuing to progress, though, is the hallmark of effective legal research.
Determine the key facts and issues
Examine your research problem for key legal issues and list the important facts; for instance, in an automobile collision the color of the traffic lights might be important, while the color of the cars would not. This is a continuous process, and you should be ready to revise the key facts and issues as you research.
Make a research checklist
Plan out your research and the types of resources you want to use and look at. Again, this list may change as you delve into your research, but a handy checklist will help you be thorough.
Do some background research
If you are not familiar with your subject, look at secondary sources. Feel free to Google the topic, but be sure you use reliable and trustworthy sources! You will want to get a basic feel for the subject. Determine whether the area is governed primarily by statutes, regulations, or case law. Find the jargon or "terms of art" that are specific to that subject. Many times, secondary legal sources will have citations to important cases or statutes on the subject. These provide a great place to start research.
Determine the jurisdiction
If you are researching a specific question, you may need to determine what jurisdiction applies. For instance, if it's an educational questions in Arizona, then Illinois cases would likely be less helpful. You will also need to determine whether it's a question of state law or federal law. Determining the jurisdiction will help you focus your research, and avoid going off on irrelevant tangents.
Search for primary law
You will need to find primary law, particularly if you are using the research in court. If you can, begin with the citations in secondary sources. Often secondary sources will provide the answers you are seeking, but you will need to verify them with the primary sources. When reading cases, look at any headnotes to find other cases on the same subject. Examine the citations in the cases to find perhaps more relevant case law. Search forward to find newer cases that have cited the one you are reading. If you are looking at statutes or regulations, use annotations to find similar statutes or relevant cases. Check for pocket parts (in books) or updates to the statute. For more information on finding cases, statutes, or regulations, look under the tabs listed above.
Make sure the law you found is still good
Laws can change; cases can be overruled. Always verify your sources are still good law.
Evaluate, revise, and draw a conclusion
As you research, continually evaluate the sources and revise your materials. You may add key facts or issues (or delete them!) or may find other sources to research. Also, as you research, think about the resolution or answer to your issue.
At some point you have to stop researching. When you do this is up to you, but if you have used a variety of sources, or if you are finding the same sources repeatedly, and reaching the same results, it may be time to wrap up the research. Often, the largest barrier to research is cost and time.
Primary legal authority are statements or proclamations of law issued by government authorities. These include constitutions, statutes, ordinances, legislation, regulations, administrative rulings, and court opinions. Primary authority is subdivided into mandatory authority and persuasive authority.
Mandatory authority is binding and must be followed. For example, under the principle of stare decisis, a lower court, such as a Federal District Court, must followed the rulings of a higher court, such as the United States Supreme Court.
Persuasive authority is non-binding and may be considered, but not followed. For example, a ruling by the Utah Supreme Court would not be binding on a Arizona court, but might be considered if the facts or legal reasoning were similar enough.
Secondary legal authorities are descriptions of, explanations of, or comments on the law. These include law review articles, treatises, legal encyclopedias, and Restatements of the Law. Secondary legal authorities are never mandatory authorities, they are only considered to be persuasive authorities.