LLRX recently posted Animal Rights in the Human Legal System, an article by Ken Strutin that describes and evaluates several resources for researching animal rights issues. The article includes descriptions of key websites, manuals, articles, ALR annotations, and organizations.
The Animal Legal and Historical Center at Michigan State University College of Law is a terrific resource for researching all aspects of animal law. The site includes a database of domestic and foreign case law, statutes, articles, and news. One can also search for briefs and historical materials.