“Posted By” using fdawn theme

I’m new to the blogging world and I’ve been testing out my blog using the fdawn theme. I love this theme. Simple and elegant.

The problem I’m having is getting the blog to list who a post was posted by. I’ll have several posters when it’s up and running and I need a way to display below the post which user posted it. Thanks in advance to anyone who can lend this unexperienced user a hand.