Finding General Encyclopedias

Encyclopedia Britannica is an extraordinarily comprehensive and reliable general encyclopedia.
Wikipedia is a free-content encyclopedia covering a broad spectrum of subject areas. Anyone can edit an entry, and consequently there is always a possibility of information being biased or incorrect. However, the site is generally trustworthy and covers a wide range of popular topics that aren't covered by Encyclopedia Britannica.

If you don't find what you need, consult a librarian.