Change the product listing layout

Hi Everyone,

I'm trying to change the layout of the product listing.
My page includes a menu with different categories, which link to the product listing.
I was hardly trying to find the view file of it, but didnt get it yet.
I wanted to add a short description right next to the product with a "read more" link.
My idea was to display only 1-2 products each row and extend the .hikashop_container div with another description-div (floated right) inside of it.
It would be really nice, if someone could tell me which view file is responsible for the hikashop_container div and it's content.

Another question comes up with the view->category (...) files.
When I first display the category-listing and then click on the category to display the products, the url (mypage.com/index.php/shop/category/19-mycategory) is kinda different to the url which is linked by the side-menu as I described before (mypage.com/index.php/mycategory).
Which file is responsible for what?

Thank you and greetings,
David