Quick and Dirty Tips, by Mignon Fogarty, Grammar Girl Blogspot
http://perma.cc/0AztTwAToiB
(There is much, much more at this website. Worth a browse . . . .)

English Usage, Style & Composition, Bartleby.com
http://perma.cc/0EUx9Jd3HK5
(Includes Strunk & White’s “Elements of Style,” H.W. Fowler, “The King’s English,” and more.)

Guide to Grammar and Style, Jack Lynch, Rutgers University in Newark
http://perma.cc/0SUMVx7Dwa

How to Write in Plain English, The Plain English Campaign
http://perma.cc/0JsVUpet3yK

Online Style Guides and Writing Skills, Mantex
http://perma.cc/0JYEshLRf6z

Writer’s Web, University of Richmond Writer’s Center
http://perma.cc/0SEh8zUwC1G

OWL – The Purdue Online Writing Lab
http://perma.cc/0Bk14D5amXN

Writing Guides,Writing @ CSU, Colorado State University Writing Center
http://perma.cc/0rK1LyLYBhW

Handouts, The Writing Center, The University of North Carolina at Chapel Hill
http://perma.cc/0JgKARJVbKF

Daily Writing Tips Blog
http://www.dailywritingtips.com/