Writing Gem is a solid example of a two column theme with a right hand sidebar:

You will note that the first column is reserved for 'featured images.' Because themes must adjust dynamically to accommodate various screen sizes for mobile devices, I recommend either a one or two column layout for your website, with the addition of a sidebar, which is covered at the end of this training.

I like the fact that in this case, one of the columns is reserved for your featured images. Just be aware that this will display on mobile as the image above or below the text of your post, not side by side.