Although I’m specifically interested in web application information, I would also be somewhat curious about desktop application development as well. This question is driven by my work on my personal website as well as my job, where I have developed a few features, but left it to others to integrate into the look and feel of the site.
Are there any guides or rules of thumb for things like color schemes, layouts, formatting, etc? I want to ensure readability and clarity for visitors, but not be bland and dull at the same time.
As for my knowledge in this area – If you hand me a picture, I have enough knowledge to reproduce it on the screen, but if you ask me to design a new interface or redesign an existing one, I wouldn’t know where to begin.
Usually, each operating System has user Interface Guidelines. For Windows, have a look here. (Edit: The links in that post are broken. But a Search for "User Interface Guidelines" on MSDN has articles about everything)
Apple has it’s own as well. Also, you may want to keep accessibility in mind.