There's a very good article at Before and After, about designing for the web. Following here are some additional, but crucial, considerations when designing a website.
When it comes to websites, how it looks is critical in attracting and retaining the right kind of attention. It is important that we are clear in what we want to communicate, and the design needs to support the tone and message we want to get across. However, what we want to say and how we want to say it is only as good as the intended outcome we expect. So, here are two ideas that can turn your website into an effective website: Think about your audience. And treat your site as a tour guide.
Here's what I mean, if you want more tech-savvy elderly people to sign-up for your newsletter, you have to consider that the color, contrast, type size and style, and tone may need to be more conservative than your tastes. And you have to consider the best means of attracting them to your site are not usually electronic, but may require direct-mail, TV ads, or magazine ads that they read.
Most businesses do not start with the audience. They are more interested in what they want to say, thinking the value is having said it. But, seldom do they realize people want a reason to value your message.
So, following, treat the website like signage in a huge building. Be the tour-guide. You have to tell people what's significant and where to go. They have to have a sense of where they are in relation to everything else. This eases the experience for site visitors, and helps them understand what you want to say and why it's important.