If you use fonts other than basic ones in web design, these will be changed to basic fonts by many PCs, which may detrimentally affect layout. Provide alternatives in your HTML for unusual fonts if you do use them. Cultivating user trust, that is, credibility. This is apparently increased by high-quality graphics, good design and writing, and use of outbound hypertext links. This means not trapping people at a site with frames or by disabling the Back button via web programming.
Web users like to know about the people behind information on the Web.
Currency of your information is crucial, as is avoiding dead links. It may be performed very rigorously in 'usability labs' or more informally. You can do storyboards of a website first, and see what a few representative web users think. Take the best and build a prototype site with several pages and test again. It has been found that each iteration increases the 'usability' of the website.