Nick Usborne is one of leading brains behind understanding/explaining how copy and content works in the online environment. His book, Net Words, published in 2002 is still one of the leading tomes on the topic.
Usborne has just completed a brand new thirty-five-page guide to writing for the web called, Writing For The Web - Seven Challenges Every Writer And Copywriter Faces When Writing For The Web.
I've read it and it's worth a purchase. Here's the good news: Nick Usborne is actually giving it away for free. In return, all he's asking is that you sign up for his e-newsletter, Excess Voice - which, as far as I am concerned, is must-read material anyway.
So, stop reading this and sign-up for Nick Usborne's Excess Voice e-newsletter and get Writing For The Web. There really is nothing for me to sell here. Usborne's work is compulsory if you're in the communications space.
While you're at it, you should check out Usborne's Blog, Nick Usborne's Excess Voice.