[PHP] Best practices for php application

[abrea]

Dear list,
Does anybody know of a url where I can find reading materials about best 
practices to organize the filesystem and variable structure of a php 
application? 
Although application purposes probably vary widely, I imagine that in one 
way or other most include adding, updating, deleting and displaying records, 
so there might be some standard or preferred procedure.
Thanks for any help
Alberto Brea
[EMAIL PROTECTED]