A statutory code is a subject-based arrangement of the laws of a general and permanent nature passed by the jurisdiction's legislature. Unlike session law compilations, which are arranged chronologically, codes are well-suited for research because they bring together all of current laws on a given subject in a relatively manageable way.
Many jurisdictions have multiple statutory codes, and the government chooses one that is "official," i.e. it will govern in the event of discrepancies. The Bluebook prefers citation to the official print version. The official version may be published by the government or a commercial publisher--it varies. See T1 of The Bluebook for the jurisdiction at issue.
Annotated codes include helpful editorial content such as: references to secondary sources that discuss the statute; references to cases in which courts have interpreted the statute (called Notes of Decision or Case Notes); cross-references to other sections or to relevant regulations; and detailed historical notes.
Unannotated codes simply provide the text of the statute, and thus often are not as useful to researchers as annotated codes. Some unannotated codes (such as the General Laws of Massachusetts) don't even provide references to the enacting session law.
Cite according to The Bluebook, Rule 12 and T1. Whenever possible, cite to the official United States Code and the official state code designated in T1.3.
Federal: 42 U.S.C. § 1983 (2012)
State: Tenn. Code Ann. § 63-1-148 (2010 & Supp. 2013)