You can't read this enough: writing for the Web is not the same as writing for print.
People read differently on the Web. They scan read—jumping quickly from one piece of content to the next. People are much more action-orientated on the Web. They get online to get something done. Words should always be driving actions.
Here are 10 rules for writing effective web content:
1. Know your reader
All effective writing begins with knowing your reader. Write for your reader, not for your ego.
Your reader is not everybody. The most effective writing is keenly focused on the specific needs of a clearly defined reader type. Is your reader a middle class, female American, with two kids, who lives in the suburbs?
Think like your reader thinks. Get to meet her. Once a month, talk to your reader. Read what she reads. Is there a common style and tone being used to reach her? Use it. Put a picture of your readers up on your wall. You shouldn't have more than 3 to 5 core reader types.
2. Take a publishing approach