Here are links to some good articles about creating content for your website.
http://alistapart.com/article/a-checklist-for-content-work : Good content is appropriate, useful, user-centered, clear, consistent, concise and supported.
http://www.dailywritingtips.com/four-tips-for-successful-web-writing/: “Good web writing is like having a conversation with the person who is reading it. ”
http://www.dailywritingtips.com/7-tips-for-writing-for-online-readers/ : You’re not writing a book – you’re writing content for a web page.
http://www.dailywritingtips.com/10-principles-of-writing-for-the-web/ : Just know these.