This is a quick response to a question from a student about style guides.

It’s just a ist of the ones I’d say were the most useful and/or interesting.

Style Guides

Yahoo! Style Guide
(excellent guide to writing for the web; covers everything from basic grammar to tips on SEO.)

Reuters Handbook of Journalism
(searchable; section headings)

The Economist Style Guide
(section headings)
Clunky page, but this is my favourite. I’d recommend buying the book.

Financial Times Lexicon
(searchable)

The Times Style and Usage Guide
(section headings; alphabetical links)

Telegraph Style Book
(section headings and alphabetical links)

Guardian online style guide
(alphabetical links)

BBC style guide
(useful for broadcasters and writers)