here's a few more resources:

  • SP - Coding Standards Good article on Coding Standards - basically, how to write code that is easy to add to, maintain, and debug. Always good!
  • PHP Code Beautifier Reformats PHP code based on your preferences, to make things easier to read etc.
  • Security Guide for PHP Excellent guide to security. Includes code snippets, examples, and cases. Easy to read, and some excellent tips. Useful as a reference guide.