THE MOST important thing you can do before charging in and developing a website is to survey your public ( the definition of public used here is the marketing one - a type of audience ). These are the people that you want to communicate to, whether it's about a product or service, or any information you want to deliver to them.
The website is for your public, so if you want them to visit and make use of it, FIND OUT WHAT THEY WANT and then PROVIDE IT.
The web makes it easy to conduct a survey. You no longer need to print, distribute and collect paper survey forms, stand on the street, or ring people up. Put your questions on the web and email your clients the link to the survey page.
Hands down, the easiest and best service I've found for this is www.surveygizmo.com. The first time I tried it, I had an online survey up and running in under 10 minutes. I didn't even need to watch their tutorial videos or read instructions, even though there are plenty of these.
You can open an account and run the surveys for free, though I suggest paying the minimum subscription. This makes it even easier, with an email invitation system support and some pre-made forms as well. And after you've built your website based on what your clients and customers want, don't stop - stay in communication with some more regular surveys. Give them a choice of products or services and find out which is important to them. Then deliver what they want most and your business will do a lot better.