Usability Guidelines
Conformance to user interface guidelines or style guides is an important pre-requisite for usability as it imposes consistency and conformance with good practice. But as published sources typically contain several hundred guidelines, they may need to be simplified and customized to project needs.
Detailed guidelines for web design are useful for both usability specialists and web designers. The most comprehensive, well-researched and easy to use set has been produced by the U.S. Department of Health and Human Services [http://www.usability.gov/pdfs].
There are also important general principles for user interface design, such as the ten recommended by Jakob Nielsen.
