Use secondary sources to learn about the law and find keywords and definitions.
Secondary sources are materials that discuss, explain, and analyze the law. They are resources about the law, not the law itself. They can help you finding primary sources and save time.
Frequently used secondary sources include legal encyclopedias and dictionaries, law reports and legal periodicals.
After identifying facts and concepts through the secondary sources, you can turn to researching primary sources.
Secondary sources can be used to locate primary sources, that is the actual law.
The United States legal system is made of three parallel systems, therefore there are three types of primary sources:
Once you have identifyed interesting cases, it is important to verify if you can rely on on.
Updating case law means checking if it is still "good law" and that you can actually use it to support your statement. You can use the Shepard's Citation system to make sure that your case is still valid or to identify new developments.