Accidental Tourist on the New Frontier: An Introductory Guide to Global Legal Research
(Jeanne Rehberg & Radu D. Popa, eds., 1998) is a very useful guide to finding both foreign law and international materials.
American Society of International Law, Research Tools webpage includes International Law Links with links to useful international law sites, the ASIL Guide to Electronic Resources for International Law, and the ASIL Insights series which provides informative essays on international law topics in the news. The Electronic Information System for International Law (EISIL) includes links to both the texts of international law documents and useful research tools. International Law In Brief is a free weekly online newsletter; subscription information is available on the web site.
Elizabeth Beyerly, Public International Law: A Guide to Information Sources (1991) is an excellent (although pre-Internet) research guide which includes indexes of authors, subjects and titles and provides lots of bibliographic information.
Duke Law School Library: Foreign & International Resources provides links to a variety of foreign and international legal materials. See also the Foreign and International Research Guides.
GlobaLex contains international, comparative and foreign law research guides organized by country and by subject
Guide to International Legal Research (2005) includes advice on how to find both primary and secondary sources, as well as sections on researching by geographical regions, on the Internet, and through online research; updated annually, it is a good place to start.
LLRX International Law Resource Page includes research guides and links to international law journals on the web. A good place to start.
Lyonette Louis-Jacques, Legal Research on International Law Issues Using the Internet is another good starting point with links to a variety of international resources including research guides.
UC Berkeley Law Library, International and Foreign Research Guides is a collection of research guides on many international and foreign topics. All guides highlight both print and electronic resources.