CIA - The World Factbook: Singapore - Features map and brief descriptions of the geography, people, government, economy, communications, transportation, military and transnational issues.
NationMaster - Singapore - Profile includes information for various aspects of the country, with a special emphasis on statistics and rankings.
TradeWatch: Singapore - Economic information, travel advice, and diplomatic relations between Australia and Singapore. From the Australian Department of Foreign Affairs and Trade.
US Department of State - Singapore - Country portal offers a map and links to Background Notes, Country Study, the US embassy and the current ambassador, press releases, fact sheets and annual Human Rights Reports.