Case Law refers to judicial opinions, the written decision of a judge deciding a lawsuit between two parties. Since much of the American legal system is dictated by the precedence of common law, researching case law is a critical component of legal research.
The Legislative branch of government creates laws in the form of statutes which are then signed into law by the head of the executive branch. There are local, state and federal statutes. Knowing which jurisdiction your issue falls under will determine which set of statutes you should consult.
The Executive branch of the government creates laws in the form of Administrative rules and regulations. These regulations are put forth with statutory authority by the government agency in charge of that area of law (for example the Internal Revenue Code is promulgated by the Treasury Department.) As with legislation, administrative regulations are created at the both the state and federal level.
Secondary resources are often the best place to start legal research because they contain analysis and commentary on the law. A secondary resource essentially "explains" an area of law. Secondary resources will also contain citations to applicable primary resources. Examples of secondary resources include:
Use the databases to search for articles on your topic. Some databases provide full-text display of articles while others only provide citations to, or abstracts of, articles. Some of the databases linked to in this Guide are subscription databases. Access is available to these databases on the campus and also off campus.