Encyclopedias are great sources for general information. They are the best place to start a research project or information search, especially if you need to build schema for your subject.
World Book Encyclopedia. There are four encyclopedias in one here and all
articles are signed by the author who are experts in their field. This information has a lot of authority.
Britannica SchoolEncyclopedia Britannica is better than ever and with four different levels for searching it is just right for everyone from PreK-12th grade and beyond