Many Web sites such as the following provide guidelines for designing GUIs:
AskTog — Essays on good design and a list of First Principles for good user interface design. The author, Bruce Tognazzini, is a well-respected user interface designer. http://www.asktog.com/basics/firstPrinciples.html.
GUI Design Handbook — A detailed guide to the use of GUI controls. http://www.fast-consulting.com/desktop.htm.
Usability Glossary — An extensive glossary of terms related to GUI design, usability, and related topics. http://www.usabilityfirst.com/glossary/main.cgi.
UsabilityNet — Covers design principles, user-centered design, and other usability and design-related topics. http://www.usabilitynet.org/management/b_design.htm.