Writer's Workshopfrom University of Illinois at Urbana-Champaign at http://www.english.uiuc.edu/cws/wworkshop/writer_resources/grammar_
handbook/grammar_handbook.htm
Guide to Grammar and Writing http://www.ccc.commnet.edu/grammar/
This is an information packed guide to grammar and writing. It covers almost every area imaginable, from word and sentence level to essay to research paper level. It also features an “Ask Grammar” form, with which you can raise questions about grammar and usage and get feedback by email. You can also give your opinions on usage in the Grammar Poll.
