Madhu Menon posts a useful article on ways in which to best guide users when they encounter a webpage that doesn’t exist or has been moved from a website. The article shows examples of bad use and also recommends techniques on what best features to adopt.
The 404 Research Lab is another useful resource site on Best Practices with guiding users when errors occur, it also has a Pros, Cons sections and a History of the 404.

Here is an interesting article by IBM’s developerWorks on Web Architecture which looks at the need to articulate messages in interfaces and how it can often be more important than usability. The article is titled, Brevity vs. Usability.

Verbosity and brevity is a much discussed area in interaction design.

What is brevity you ask? Here is a definition by Dictionary.com, and refers to being consise in word use, an example includes, the text in navigation items should be short and descriptive.