Educational Search Engine

Google Scholar - This must-have search engine for research lets you easily find relevant scholarly literature, such as books, theses, abstracts, and articles, across many disciplines and sources
Microsoft Academic - a semantic search engine, not a keyword-based one

Online Reference Tools

Merriam-Webster Dictionary - official site includes online versions of the collegiate dictionary and thesaurus, also includes the talking dictionary
Cambridge Dictionaries Online - official site includes online versions of the Learner's Dictionary, Dictionary of American English, Idioms and Phrasal Verbs
The Free Dictionary - a talking dictionary with a comprehensive thesaurus and simple word-to-word translation machine
Wikipedia - the free encyclopedia online which everyone can edit. It is also offered in Spanish, German, French, Japanese, Polish and Swedish. However, this is not a reliable source for academic researches.
Citation Machine – an easy-to-use citation generator
Research and Documentation Online - provides style manuals and sample papers in MLA, APA, Chicago and CSE formats
 

Grammar

Grammarly – a free online automated grammar checker
Modern English Grammar - the online English grammar hypertext book

Online Newspapers/ Magazines

 CNN Interactive
BBC

Wall Street Journal
World Net Daily - a free press for free people 
New Scientist
Big think
Project Syndicate - provides incisive perspectives on our changing world by those who are shaping its politics, economics, science, and culture all over the globe.
 

E-Books

Project Gutenberg – a library of over 60,000 free ebooks
Open Culture - free cultural and educational media
The Literature Network provides over 1200 full books and over 2000 short stories and poems by over 250 authors
Classic Short Stories

Poetry Foundation