Here is a resource list that provides help with everything from A - Z, RefDesk.com. It begins with:
11 Rules of Writing - This site is a concise guide to some of the most commonly violated rules of writing.
100 Words That All High School Graduates � And Their Parents � Should Know - The quality of a person's vocabulary has a direct effect on his or her success in college and in the workplace. In response to parents' misgivings over the quality of their children's education, the editors of The American Heritage� College Dictionary have compiled a list of 100 words they recommend each high school graduate should know.
A Rulebook for Arguments, by Anthony Weston - "This book begins by discussing fairly simple arguments and moves to argumentative essay at the end."
All About Writing! - Over 200 pages of articles on writing and is designed to help everyone improve their writing and editing skills. The process involves looking at grammar, punctuation, and structure in a way that allows you to re-evaluate your writing style and improve the way you communicate in text.
American Heritage Book of English Usage - A powerful, practical and authoritative guide to contemporary English usage that will help you make intelligent decisions when communicating in speech or writing. Site presents sound guidelines and specific controversies in grammar, style, and word choice.
Antagonyms - words that have opposite meanings (e.g., "bad" can mean bad or good depending on usage).
AskOxford.com - Free English language reference site from Oxford University Press. The site has a range of resources including dictionaries, a thesaurus, word games and writing guides as well as the opportunity to put any language related question not answered by the site to OUP's resident language experts.
Basic Elements of English - Grammar tutorials offered by the English Department at the University of Calgary.
Basic Guide to Essay Writing - a step-by-step guide to writing a basic essay. Includes links to other on-line essay resources.
Blue Book of Grammar and Punctuation, The
Book of Cliches, The - "The Book of Clich�s lists phrases to say in times of trouble in a number of categories."
The Chicago Manual of Style: FAQ - Site answers some of the questions ask of CMS staff that commonly vex writers and editors.
Cliche Finder - Site has a list of 3,300 cliches, and can be searched by keyword.
ClicheSite.com - Site has a list of cliches 'As long as your arm,' complete with definitions and explanations along with a 'Cliche of the Day.'
Colorado State University Online Writing Lab
Common Errors in English - site which simply and entertainingly explains a number of common spelling and usage errors in English.
Commonly Confused Words - An alphabetical listing of frequently used and sometimes misused words, with explanations and examples of proper usage
And, these are just some of the ABC's of it. The list continues through the letter 'Y'. All of this amazing information can be found at: RefDesk.com
Enjoy! Hope you find something useful.