If you've ever looked at your code an wondered about its commenting, if there was a kind of "best practice" to follow when it comes to its structure, you should read this article from Andrew Podner about docblocks.
The subject is how to properly document code with PHP comments and docblocks. This one took a while for me to really just accept as a part of the development process. To me now, the comments are now just as much a part of the application as the code is. I believe it is that important. With IDE's today, there really is no reason not to have good documentation in your source code.
He talks some about his own reluctance at first to use comments and how it helped him remember what his thought process was behind parts of this code. He includes an example of a typical docblock structure, showing the general description, parameters and a "return" value. He also includes something interesting in the topic of documentation - good variable names. There's links included to two tools that can take these standardized comments from your code and build HTML documentation from it - phpDocumentor and ApiGen.
You can find out more about the PHP docblock standards from this site.