Blog Page Layout
If you prefer to show a picture and excerpt of your blog posts rather than the entire post on your blog archive page (www.yoursite.com/blog) - Navigate to Genesis > Theme Settings and scroll down to Content Archives.
If you'd like your image to float to the left of your excerpt, select left from the "Image Alignment" dropdown.
You can also choose to display a content limit, and adjust the amount of text that shows to your liking.
Be sure and scroll to the bottom of the page and click "save changes".