Okay, I guess I should have added my answers here instead of above in the comments. So, I'll try again.
Dictionary.com gives all the source references on one page, from English and slang to science, computing, and medical dictionaries, including History and Origin, all from specific dictionaries. It includes nearby words, related searches, and all words from the root.
RhymeZone.com gives rhymes, thesaurus, similar sounding words, quotations, homophones, letter matching search, pictures, and even Shakespeare references. It has links to the Bible books, and famous quotes, and several links to specific genres produced by Shakespeare. I use this site almost daily.
The Purdue OWL is an Online Writing Lab for tutoring or learning to writing well in English. I recommend taking a look, also, at the OWL site map to see the range of subjects covered.
I recommend the site EngVid for clearing up questions about grammar rules, and other English language dilemmas. There are videos for over 500 subjects on that site, all related to English. Some people learn better through watching demonstrations on whiteboard. These videos work well for tutoring, too.
I also believe you need a link to the Middle English Dictionary. It may be an obscure language, but we still study the Canterbury Tales by Chaucer, and John Gower's Confessio Amantis.