The "CIA World Factbook" has become one of the most trusted and reliable free resources for learning about different nations, their condensed histories, political affairs and societal makeup. The book contains a profile of every country on the planet and goes into considerable detail about each nation's main business industries, exports and transnational issues. This makes the resource particularly valuable when learning about unfamiliar countries and how they compare to others around them.
Google Books is an ideal resource for teachers and students who are interested in quickly and conveniently searching published materials for specific information. The website enables many books to be read in their entirety for free, and also has hundreds of viewable magazines that have been electronically scanned and transformed into digital information. The resource is especially useful for finding reading material that is currently out of print.
Hosting a large array of teacher resources, educational games and reference/exam material, Top Marks is a useful website and worth exploring. The website enables visitors to browse either by subject or age group, making it particularly useful when seeking information relevant to the age of the students.
The oldest digital library in the world, Project Gutenberg has been offering digital versions of published books since 1971 -- originally through the use of small academic computer networks. With the growth of the Internet, the project has expanded dramatically. It now offers thousands of books online, making it a valuable resource for research on subjects such as agriculture, law, religion, crime, among many others. The project is run by volunteers who group books by category and subcategory for easy browsing.