Use this code to echo your div’s ID
<?php $sidebar_layout = get_post_meta($post->ID, 'sidebar-layout', $single = true); ?>
<div id="<?php echo $sidebar_layout ?>">
<div class="content">
...
</div>
<div class="sidebar">
...
</div>
</div>
If you want to apply styles according to the selection the user has made then change your style sheet as follows:
#left .content{ ... }
#left .sidebar{ ... }
#right .content{ ... }
#right .sidebar{ ... }
#none .content{ ... }
#none .sidebar{ ... }
I hope this helps.