Apart from html5, Css3 what is needed to create an E-Commerce Website?

You will need some type of back-end programming skills, for example PHP or Ruby on Rails (among others) and probably some database skills (like MySQL).

In the PHP development track you will build a simple e-commerce site; you could take a look at that track and clear all your doubts.

You could also use WordPress to build e-commerce sites. Take a look at this course: http://teamtreehouse.com/library/ecommerce-with-wordpress-and-woocommerce

If you use Word Press you will likely need some PHP skills as Word Press is build with PHP.

My advice in short:

a. If you are under the clock to build your site, go straight to the ecommerce with wordpress and woocommerce course. I'm not certain of how much PHP skills you will need to go through the course but you will certainly need some background on WordPress as it is an intermediate course.

b. If you have time and you want to get a deep understanding of what's happening, do this: PHP Development track -> WordPress Development Track -> Ecommerce course.

By the end of option (b) you will be in a solid position to build, maintain and improve your store on the long run.

Hope this helps,

Sergio

Thanks for the information Sergio!