This is page 4 of a 4-page demo about using Joomla's "category blog" to display stuff in a grid format.
For this page, I have added intro-images (in the tab "Images and Links") to the articles. These images are clickable (Note: this requires your template to make the intro-image clickable - not all templates do that). For practical purposes, you will need to add some information about the article - show the title, or add the name above the "read more", or edit the images in a photo editor and put a title on them.
A real life example? See this sponsor page. Here, the sponsor's name is in the article title for sorting purposes, but the images are added in the article body, and they include an external link (to the sponsor's website). There's a photoshop template for making the images. Once it's all set up, adding or removing a sponsor is a breeze.