Legal information available online
General purpose information
The Law Library of Congress’s Guide to Online Law includes legal information from over a hundred different countries and all fifty states.
The Legal Information Institute has guides to 130 different areas of law.
The Armed Forces Legal Assistance site is also a great resource for basic legal information, aimed at service members, but often generally helpful, on topics including consumer law, family law and trusts and estates.
Your State’s Bar Association may also offer information specific to your jurisdiction.
The ACLU's pamphlet "Know Your Rights When Encountering Law Enforcement" (pdf).
Copyright, patent and trademark
Small Business Law
The U.S. Small Business Administration's Small Business Planner.