How to Write Clearly: Write with purpose, reach your reader and make your meaning crystal clear (Freelance Writing Essentials) eBook : Albrighton, Tom, Kessler, Doug: Amazon.co.uk: Kindle Store
Plain Words is one of the earliest and most influential books on the subject of clear language. First published in 1948, some of it is now dated and – as you might guess – there's no mention of the good ol' internet. But it's still a great read and worthy of a place on your bookshelves.