CIA World Factbook: Colombia: Features a map and brief descriptions of geography, economy, government, and people.
Colombia - A Country Study: Overview of life, history, and culture by the US Library of Congress.
Infoplease.com: Colombia: Very basic information on the land, its people, history and government.
Lonely Planet World Guide: Destination Colombia: An in-depth look at Colombia, its history, its culture, and what it offers to visitors today.