CIA World Factbook
Succinct and factual details about each country; country rankings.
Detailed histories,economic and political conditions, as well US relations with each country.
Europa World Year Book (print)
Authoritative and substantive country profiles.
Country Commercial Guides
Political and economic conditions and regulations that affect doing business there.
Country Studies - Library of Congress
Detailed profiles coevr history, economic conditions, social structure, etc.
OECD Country Information
Overviews and statistics on OECD member countries - about 30 countries included.
BBC News - Country Profiles
Overviews and BBC news by country.