Being an eCPPT I completely agree with Armando that you don't need to be a programmer to complete the course but you still should be able to understand the code. Most of the php required for the course can be easily learned from w3schools.com
http://www.w3schools.com/php/default.aspBut, to get the most out of the course, I would suggest that you learn enough php to be able to set up a basic website, prior to joining the course. Learning vulnerabilities without understanding the language gives you an abstract view of that vulnerability. If your objective of joining the course is to LEARN and not just to earn one more certification than I would definitely suggest learning enough PHP and C (Focus on pointers) before starting web application and system security modules.
You can even start the course and learn PHP and C alongside. In that case I would suggest starting out with network security module first as it doesn't require ant programming skills and learn PHP or C side by side. Then, once you're comfortable with PHP or C, you can jump to web application or system security modules.
What should I do in case i decided to take the ecppt?What are the required programming skills?
I didn't know any PHP when I passed the certificate exam.
what books should I read before applying to eCPPT?
'The Web Application Hacker's Handbook' will be a good companion.
Other books I read/consulted:
Counter Hack Reloaded by Ed Skoudis.
The Shellcoder's Handbook.