Criteria

Design
A clear thought out design creates easy to read and beautiful websites allowing users to focus on the content and not the flow.

Navigation
Probably the most used tool on the web is providing a menu to navigate your site. Users navigate differently, however adding a combination of menus, text links and graphics will ensure that every user finds what they are looking for, or what you want them to see.

Readability
Size, color, spacing, general overall size and especially placement are probably the most important part of usability. Users generally won't read your text thoroughly in a word-by-word manner and will often ignore the welcome and move on to more meaty substance.

Content
How much is enough? How much is too much? And, most importantly, how much is just right? Now more than ever, delivery of that content is what will truly set you apart. Create content that users will read. Make it current, make it count.

Cross-browser/Devise Platform Consistency
Internet Explorer, Firefox, Safari, Netscape, Opera... these are just a few of the browsers that you’ll need to keep in mind when designing. In addition, the iphone, ipods, Smart phones, PDAs, Treo, Palm and other devices now come with full web browsers and have to be taken into consideration with website design.

Scalability
Planning for what’s to come is as important as what is already on the site. Develop your site not only for great usability but also for scalability.