The American Heritage Dictionary of the English Language
"The online searchable American Heritage Dictionary is your best source for quick, accurate, basic information such as definitions and pronunciations."
The Blue Book of Grammar and Punctuation
"Use this site to find the answers to your questions concerning proper English grammar and punctuation."
Guide to Grammar and Writing (via Capital Community College, Hartford, CT)
This online guide answers many questions students have about writing, from fine points of grammar and paragraph structure to essay organization and research paper citation formats.
Good writers are multiply literate, able to choose appropriate styles for different purposes. These guidelines apply to writing formal English where, as in academic contexts, it is important to write clearly for an unknown or open-ended readership. This checklist is an ongoing collaboration between Matt Silliman and David Johnson; we offer it to our students and colleagues for their use, adaptation, and amusement. [Updated 2/2014]