General Reference

Bartlett's Familiar Quotations  is a collection of passages, phrases and proverbs traced back to their sources in ancient and modern literature.

Merriam-Webster Dictionary and Thesaurus  allows the searching of word meaning, pronunciation, origin, synonyms, and more.

Time and Date is a collection of calculators, converters, and other tools relating to time, date, weather, and the seasons.  

Wikipedia is a free encyclopedia that anyone can use and edit.