A Study of Web site Navigation Methods evaluates six different navigation methods for the same web site to choose the one the most convenient for users.
According to the study, the most convenient navigation methods are a directory-style menu (Yahoo-style) and drop-down menu. Unfortunately, when considering pros and corns of both navigation methods, the study [...]

The Principles of Design explains the core elements of visual design:

Balance
Rhythm
Proportion
Dominance
Unity

Make sure to read the article. It will help you make better user interfaces.

I’m making up a new site and this research on layout usability was very useful for me. I hope you will find it interesting too.
Three layout methods are studied:

“Fluid” layout (Has the flexibility to expand and contract along with the size of the window).
Positioning the content such that it is centered within the [...]