The main database for researching state statutory law is Lexis Academic. After opening Lexis, choose "US Legal" from the side menu and then choose "State Statutes, Codes & Regulations".
On that page, you can choose the state you would like to search in by using the "jurisdiction" drop down menu.
Lexis Academic provides annotated state codes. These are publications of state laws organized by topic, with notes for each section of law that provide information about the history of the statute and any courts that may have interpreted the law.
Another important source for state statutory law is the websites of the state legislative bodies. Often times the websites will have explanations of how a particular state's legislative system works, links to statutory law and legislative history available online, contact information, and other helpful resources for legal research.