Here there are some links to articles very useful and interesting and some reflections about them:

• Pixel Dimension Indicators Is this really useful if there are already tools that can tell you the size, the color, the font, etc just by selecting the item?
• 10 Principles Of Effective Web Design ... let us not forget that the user needs to feel gratified, instantly.
• Don't Make Me Click ... don't let interaction is translated into effort.
• CodaCoza ... if someday I learn some design stuff, I want to do it for things like that.

Note: doing my homeworks, trying english (second time)!