www.poynteronline.org — "All you need to be a better journalist" (including a series of pithy tip sheets on writing and editing).
www.plainenglish.co.uk — The Plain English Campaign's free guides include an excellent 17-page A-Z of alternative words and phrases (to print out or download).
www.theslot.com — Legendary, curmudgeonly, fallible, fascinating and provocative US site for copy editors. The Sharp Points section will inspire and infuriate you.
www.visualthesaurus.com — Intriguing, interactive 3D thesaurus. A unique, mutated cross between Roget's original "classed catalogue of words" and an art-gallery mobile.
www.worldwidewords.org — Huge (1400-page), brilliant, pedantic, obsessive, British site for those with the urge to burrow deep into the meanings, usages and etymologies of words.
www.corporatestory.co.uk — Interesting, literate commercial site for a growing European PR firm we are proud to endorse. Even uses a proper piece of sustained narrative fiction to pitch its wares.
www.meetthepress.com — Europe's top PR training firm runs 40 courses a year, ranging from the Absolute Beginners boot camp to seminars with editors and ex-editors from the Sunday Times, the FT and other key titles.
Mark Israel's FAQs for alt.usage.english — The AUE newsgroup is where profs and pedants gather to put the English language to rights. The FAQ has a splendid, daunting list of style rulings, derivations and unresolved debates. Love it or hate it.