Customise Post layouts on a page

Hi there I am Dynamic Website Builder and have got myself a little confused with regard to the custom options. I would like to display my blog posts with custom sized images only clicking to go to relevant blog page (something similar to attachment) please can someone advise me. I;ve created my page template for my images. Am I creating :
1 - a widget Are
2. Hook Boxes

I am not sure which setting to choose under the Genesis Doc drop down. The same goes for the Hook boxes.