If you write on a regular basis, you’ll need to refer to one or more style guides. Many book publishers, for example, use the Chicago Manual of Style, and most newspapers and magazines use the AP Stylebook. Daily Writing Tips gives good advice on these and other style guides, many of which are available online.
The two most frequently cited American style guides are the Associated Press Stylebook and Briefing on Media Law and the Chicago Manual of Style. Both have online editions, but they are not free. Individual annual subscription rates: AP Stylebook $25; CMOS $30.
The current Amazon price for the print edition of the 2009 AP Stylebook is $11.37. I paid $18.95 for my copy earlier this year. The AP book is very easy to navigate so I don’t see any advantage to subscribing online.
The usual price for the print edition of the Chicago Manual of Style is $55. Amazon has it for $33.65 at the moment. For me the search feature of the online edition is worth the $30 subscription fee.
For our readers who use British English, the BBC has a free downloadable PDF: The BBC News Styleguide.
Another British online freebie is the Guardian, Observer and guardian.co.uk Style Guide.
A free nonacademic online American style guide is the National Geographic Style Manual.
An old edition of Strunk and White’s Elements of Style is available free at Bartleby.com/. Be aware that changes have been made in more recent editions . . .