1) Create clear call-to-actions that lead your visitors to measurable, tangible goals

Think of your website as sales tool that can be constantly and scientifically improved.  Every page that your visitors land on should have a call-to-action that leads them to the next step of your sales funnel.  For this to happen, you'll need predefined business (or conversion) goals.  Ex: generate a lead through an emailable contact form, through a trackable 1-800 number, etc..  Next, determine the natural steps that a user would follow to reach your goal.  Ex: Your natural user flow (also known as 'Sales Funnel') might look something like this: Home Page --> Services Page --> Contact Page.  On the Home Page, our call to action may read: "Learn About Our Services!"  The Services Page call-to-action may read "Contact Us For More Info."  And the Contact Page call-to-action may read: "Fill Out Our Form for a Free Quotation".  It's a very straightforward way of increasing your website's conversion ratio and overall usability.

2) Build an intuitive information architechture

Information architecture is often something that is overlooked in the development process of a website.  As a website is extended and more pages are added it becomes increasingly important to have a natural page hierarchy.  This will make your site more manageable for administrators and more usable for visitors.  Website's are often constructed with a 'flat' information architecture that makes it very difficult for both users and search engines to prioritize and categorize information.  A sound information architecture might look something like this: