Federal Statutes: A Beginner's Guide. An excellent overview, by Barbara Bavis of the Law Library of Congress.
The United States Code is where federal statutes end up permanently. It is arranged by topic.
Often a federal department or agency is authorized by Congress to write regulations that flesh out details left unspecified in the U.S. Code. These regulations are also codified, in the Code of Federal Regulations. The numbering is parallel to the U.S. Code numbers.
New York State's codification is called the Consolidated Laws of New York. It is also arranged by subject.