Below is an interesting interview on the biggest mistakes that most of us make in building our websites. The key points are that your site must be;

• User Friendly
• Have a Call To Action
• Be less cluttered
• Vertical Architecture-with sections and sub-sections
• Easy to read text
• Communicate your offer up-front.

The message is premised by the fact that if visitors have landed on your site via Google SEO-then you've probably got 3-5 seconds to capture their attention.