For foreign law (the domestic law of a foreign country), try LC Guide to law online:
The American Society of International Law's mission is to foster the study of international law and to promote the establishment and maintenance of international relations on the basis of law and justice.
International Law is the law between nations or between citizens of different nations. Private international law focuses on individuals from more than one country, usually involved in business or commerce. Public international law is the custom and practice of sovereign states as they deal with each other and with individuals. Treaties are binding agreements between or among sovereign states in written form and governed by principles of international law.
Many multinational treaties have their own websites or websites run by an NGO. These websites tend to have up-to-date information ratification by various parties, the details of any reservations, and many documents that assist in the implementation of the treaty.