ACES, the American Copy Editors Society, is a non-profit 501(c)(3) education and membership organization working toward the advancement of copy editors. Our aim is to provide solutions to editing problems, training and a place to discuss common issues.
Source: About ACES
The AP Stylebook is a writing style guide for journalists. It is published and updated annually to reflect changes in writing style and new guidelines.
Updated regularly since its initial publication in 1953, the AP Stylebook is a must-have reference for writers, editors, students and professionals. It provides fundamental guidelines for spelling, language, punctuation, usage and journalistic style. It is the definitive resource for journalists.
Source: AP Stylebook http://www.apstylebook.com/?do=what_is