The sample chapter of Essential PHP Security for MySQL's Developer Zone is now available:
This chapter discusses form processing and the most common types of attacks that you need to be aware of when dealing with data from forms and URLs. You will learn about attacks such as cross-site scripting (XSS) and cross-site request forgeries (CSRF), as well as how to spoof forms and raw HTTP requests manually. By the end of the chapter, you will not only see examples of these attacks, but also what practices you can employ to help prevent them.
I hope you enjoy it. :-)