The world factbook will give you current information about countries. Another favorite website is the IRS site . For additional information, try Taxes . If you are trying to find information on a subject and you just can't find it in book form, try this mega search-engine which searches several different search engines at a time. Links to biographies, historical documents, audio and video files, and other presidential sites are also included.
Historical documents includes such documents as the U.S. Constitution.