Adding thumbnails to posts

Okay, WP world. What I’m wanting to do is to add image thumbnails to each post. Let’s look at my website to get a grip on what I mean.

http://www.debasedtothis.org

Below the slider, you will see all previous posts with my avatar to the very left. Along with that avatar, I’d like to have a thumbnail image that quickly sets the mood for the story. If possible, it would be great to display the author name. Is there a known plugin that can handle all of this?

Thanks in advance.