Great answers here, just wanted to add a link to Easy-WP, a recently released "admin theme" which makes the entire backend super-simple for your content-focused admins:
http://wordpress.org/extend/plug…
Disclaimer: I'm not an employee or paying client of easy-wp, I've just found it extremely useful in making the WordPress admin interface less scary to CMS newbies, who might otherwise gravitate towards Google Sites or Joomla!.
Is there a way to change the skin/theme of the admin panel of WordPress?
deano.com 