• Merriam-Webster − Like it or not, this is the US’s Declaration of Independence from the OED.
• Memidex − An excellent cross-reference dictionary system, just to be absolutely clear on meaning.
• Google Ngram Viewer – A good start for tracking linguistic shift (in literature, at least).
• notengoenie − The handiest supplier of special characters for print and online writing.
• GrammarBook.com – The Blue Book of Grammar and Punctuation.
• Common Errors in English Usage − A very helpful, very important guide for nuance and expression.
• IEEE Computer Society Styleguide − A guide to dressing up and standardizing online copy.

Research

• White Pages − With reverse phone and address searches and new links to social media, this is increasingly handy.
• Google Scholar − Access to scholarly journals, as much as you can read without buying an account.
• Etymonline − This is a delirious, delicious indulgence in word origins, learning the amazing stories behind the words we use.
• Wordnik − A beautiful, robust compendium of the most obscure, archaic words with cited examples of usage.
• Hoovers − If you need to research a corporation or its admin, this is frequently a great place to start.
• Internet Archive − Need to know what used to be on a website? Check the Wayback Machine.
• ipl2 − Merger of the Internet Public Library and the Librarians’ Internet Index (closed, but still works).
• US Patent/Trademark Office – For looking up who owns what name and when last they had it.

Images

• Google Images – Among the best image search sites online.
• Tin Eye – This was the image search website before Google got on the bandwagon.
• ASCII 2D – A Japanese site that pulls images (primarily illustrations) from an entirely unique database.
• Yandex – If you can’t find your image anywhere else, you might as well give this Russian site a try.

Reading

• Project Gutenberg – A broad collection of free-to-download texts for computer or e-reader devices.
• Google Books – Another enormous online collection of books, magazines, newspaper, what-have-you.
• Library of Congress – The truest treasure trove of publications and media. Movies, music, pictures, writing—it’s magnificent.
• Distributed Proofreaders – Another online library dedicated to preserving classical works through volunteer effort.