Guide to Grammar and Writing
Award-winning site from Capital Community College, Hartford. Includes detailed tutorials on grammar and writing at the sentence, paragraph, and essay level; PowerPoint presentations and interactive quizzes; extensive links to writing-related sites; and an "Ask Grammar" feature where you can get answers to questions on grammar.
http://webster.commnet.edu/HP/pages/darling/original.htm

English as a Second Language Site
This site by Rong-Chang Li contains general information on writing and grammar as well as an extensive list of links relating specifically to Business English.
http://www.rong-chang.com/

Purdue University Online Writing Lab
This excellent site includes 130 instructional handouts, extensive links to writing-related sites, an e-mail grammar "hotline," help for ESL students, and much more.
http://owl.english.purdue.edu/

Online Technical Writing
Austin Community College
This comprehensive site includes information on many of the topics discussed in your textbook, including document design, business correspondence and resumes, proposals, instructions, oral presentations, the writing process, audience analysis (with an interactive "audience planner"), and team writing. http://www.io.com/~hcexres/tcm1603/acchtml/acctoc.html