Regarding Using you or us in articles?
In March, Alex Homer blogged about using second person (you) or first person (I/we) when writing books.
He prefers writing in first person plural, but he says many book publishers change the text to second person.
The primary reason for this may be that since the author is already known, there is no need to state “I” or “we“. For example, Alex Homer is not going to write throughout the book something like:
“In this book, Dave Sussman will demonstrate new features in ADO.NET 2.0. He will also show how to implement them in advanced Web applications. The first step Dave must perform is ...“
It's more logical that writers direct their text at their audience, “you” or the “developer“, etc.
But, while this issue can be debated (of course), what's more important from a pure quality of writing standpoint is that authors be consistent in their usage.
Unless the editor specifies which one to use, choose one and stick with it.