How do I replace title with logo in twenty eleven

I have created a site:

http://www.primadonnadesigns.net

I would like to replace the space where the title and description should go with a logo. I tried a few of the threads instructions but don’t seem to get the right result.

I tried replacing in header.php the section:
<hgroup>
<h1 id=”site-title”><span>” title=”<?php echo esc_attr( get_bloginfo( ‘name’, ‘display’ ) ); ?>” rel=”home”><?php bloginfo( ‘name’ ); ?></span></h1>
<h2 id=”site-description”><?php bloginfo( ‘description’ ); ?></h2>
</hgroup>

I tried to replace the bloginfo( ‘name’) with a url…I just don’t know how to do that properly. When I added the url…the actual url showed up not the img. So I added img before…and got syntax error.

<hgroup>
<h1 id=”site-title”><span>” title=”<?php echo esc_attr( get_bloginfo( ‘name’, ‘display’ ) ); ?>” rel=”home”><?php bloginfo( img:’i entered the url here’ ); ?></span></h1>
<h2 id=”site-description”><?php bloginfo( ‘description’ ); ?></h2>
</hgroup>
<? blogname