English grammar and punctuation - web resources

Comprehensive Grammar Guide from Capital Community College Foundation

Conquering the Comma – PowerPoint slides from Purdue University Writing Lab, dealing with clauses, sentence structure and commas

PowerPoint Presentations on common grammar errors from Capital Community College Foundation

English Page - grammar tutorials and exercises

Self Study Grammar Quizzes from the Internet TESOL Journal

NASA handbook for technical writers and editors.
Everything you probably never wanted to know about grammar and punctuation - 101 riveting pages of grammar!

Online Writing Lab at Purdue University. Includes strategies for improving your writing and focuses on both larger issues and sentence and word level issues

Proofreading for Common Surface Errors: Spelling, punctuation, and grammar from Indiana University