A powerful plugin that will allow you to add custom code or CSS to your header, footer, sidebar, content or feed.
If your question isn't listed here, please post a comment at the WordPress.org support forum. I monitor the forums on an ongoing basis. If you're looking for more advanced support, please see details here.
Several customization options are available via the Settings page in WordPress Admin. You can access this via Settings » Add to All
For more information, please visit http://ajaydsouza.com/wordpress/plugins/add-to-all/