Common Errors in English
http://www.wsu.edu:8080/~brians/errors/
A list of common and sometimes funny errors in the English language.

Grammar, Usage, and Style
http://refdesk.com/factgram.html
A list of references for grammar, usage, and style when writing papers for school.

Guide to Grammar and Style
http://andromeda.rutgers.edu/~jlynch/Writing/
Grammatical rules and explanations, comments on style, and suggestions written by a teacher.

Guide to Grammar and Writing
http://webster.commnet.edu/grammar/index.htm
Find information about grammar and writing.

Online English Grammar
http://www.edunet.com/english/grammar/toc.cfm
A site with links to many helpful pages of English Grammar instruction and information.

Preliminary Grammar Book
http://62.6.162.42/intro.html
Twenty-two sections on the use of basic grammar, with examples, glossary of terms and exercises.

The Blue Book of Grammar and Punctuation
http://www.grammarbook.com/
A wonderful resource for correct grammar information.