A question from my inbox:
Q: I just started a new job, and one of my side jobs is to update some material for our division on the external website. Do you have any rules of thumb on website content? (e.g., viewers spend avg # seconds per page; graphics to text ratio, etc.).
A: Some people do establish rules and ratios for web pages — ratio of key words to all text is a big one. But I find really every site is different, and I think for most sites applying a metric is as likely to give a false sense of security as it is to help.
I would suggest thinking instead about use cases: what are the situations in which someone will come to the website, what will they be looking for, how can you fill their needs. Come up with the major cases you can think of, prioritize those, and work on designing the pages and navigation so that priority visitors can answer their questions as quickly and fully as possible.
I also recommend getting the book Don’t Make Me Think: A Common Sense Approach to Web Usability by Steve Krug. It came out 5 years ago, but it’s still the best text I know for thinking about how a web site should work.