The Visa requirements for each country depend on which country the traveler is from. Usually the best place to obtain information about Visa requirements is therefore your local Embassy or Consulate of the country you are traveling to. The U.S. Department of State is maintaing a list containing the Visa requirements for U.S. citizens to practically every country. Please note that Visa requirements can change quickly.
A Passport is needed for all international travel with a few exceptions. The rules and regulations for the exceptions can change quickly, and obtaining a Passport can take several weeks, so it is advisable to maintain a current Passport at all times.
Department of Foreign Affairs
* Visa requirements for Canadian citizens
Foreign & Commonwealth Office
* Passports & Visas for British Travellers