On PHPMaster.com today there's a new tutorial from Sneha Heda looking at error handling in PHP - the types of errors that can come up, how to throw your own and how to catch them appropriately.
Errors are the most common event a developer faces when programming. [...] To help reduce the number of errors in your code, and to mitigate their effects, proper error handling is essential in your web application. This article is a crash course in PHP error handling. You’ll learn about PHP’s built-in error reporting levels, and how to handle errors with custom error handlers and exception handling.
She starts with the different error reporting levels PHP offers, everything from the lightweight E_NOTICE out to E_ALL|E_STRICT. With this as a reference, she shows how to create a custom error handler (using set_error_handler). Also included is a look at exceptions and some of the more detailed information that comes with them - line numbers, messages, file the error was thrown from, etc.