I am going to develop Epaper website

This kind of task is suited to a well-rounded developer or small team of specialists, since it will involve multiple languages. You'll be needing PHP and JavaScript knowledge, HTML and CSS and maybe some XML as well.

To begin with you'll need to design the look and feel of your site. I recommend drawing out how you want it to look, then wireframe it in HTML/CSS. Once you've wireframed it, you can build the front-end and get it looking exactly how you want.

After this stage is completed, it'll be time to move on to the server-side and begin programming in the functionality you require. You'll probably want to start by building a back-end control panel where you can administer your content, much like a content management system. You'll be needing such functionality as article editors (which work with a database), page display options, user permission functionality, ratings, etc.

Once you've got a functional administrator's control panel on the go, you'll want to begin writing some front-end functionality to allow your content to be displayed (from the database).

Take a look into the factory design pattern, it might be useful for you here. You may also be interested in the MVC framework.

Good luck.

i am a designer of websites but from where i can learn develop back end

If this is a site you will be building and managing yourself without the aid of developers, I would suggest you look at using Wordpress which was designed to handle this type of site. Depending on how simple you would like the site to be, it shouldn't be too difficult (and shouldn't take a slew of designers or programmers to complete). If you want very specific customization, then you will in deed have to begin looking at hiring expert help. Do a Google search for "best news themes for wordpress" to find news-based themes or Worpress. Good luck.

Thank you all for your valueable suggestion.
Is it possible to design it in wordpress