
The User Experience is probably the single most important thing to consider when creating a site. Without a good user experience, SEO is pointless. What good is it to get to the top of the search engines if visitors to your site can't figure out how to use your site?
A couple of years back, I did research for a fitness company that needed to find equipment. I had 126 company websites to visit to asses what kind of equipment they had, how much it would cost, what the quality was, etc. I only ended up contacting 31 companies. The biggest reason; they were the only companies that had websites that were good enough to use. Please notice that I didn't say that they had "great" sites, I said they were "good enough".
$2.1 MILLION in contracts was lost by the companies with bad sites. I had so many to visit and such little time to do it, that if I couldn't use their site to find what I was looking for within a minute, I HAD to move on. Unlike the 3 Second Rule, I gave them a FULL MINUTE before I moved on.
I was AMAZED by how many sites were beautiful, but useless. Many companies had contact information that was difficult to find, poor navigation, security warnings, slowness, and sometimes I couldn't even figure out what the heck it was that a particular company did! If I go to your company's website, and I click through a half dozen pages and can't figure out what your company does, even in the most general sense, I've given you a more than fair chance.
As I was doing this research, I just kept thinking, "Can't these companies just make a simple site that says what they do?!" That's all I wanted. Just by doing the MOST BASIC things to their websites, these companies would have had a chance to get a piece of that huge contract I was working with.
FREEBIE!! As an SEO professional, this is probably the most important image I have ever seen on the internet. I give it to all of my prospective clients as a gift, because I want them to win, with or without me. This image was created by cognitive psychologists and user interface experts. The experts that created this actually tracked the eye movement of thousands of people across thousands of websites. This image is a basic website layout. The different areas are shaded based on how much attention a visitor pays to each area. Darker areas are where users pay the most attention and lighter areas are where users pay less attention to. Use this image wisely!

Cheers,
Chris