As the codex says, you can put <?php the_meta(); ?>
inside the code for your post (The Loop, most likely found in the file titled “Single Post” on your Theme Editor page) and it will pull the Custom Fields for you. Styling them is in the CSS under the “postmeta” div (I believe, I know it’s listed in the codex) to get the colors and borders, etc. that you want.
Positioning is another animal that I’m not too sure on, but that should be enough to help you experiment a bit.