Here you go, drmodule.
1. Define a top graphic.
Firstly, design your new top graphic and upload it to your web space, or add it to the WordPress Media Library. It will be best if your top graphic is 990 pixels wide, and it can be any height you like – 100 to 150 pixels is a good height for a page header.
Appearance > Design Settings, under Top Graphics click on Add new Top Graphic. Give your top graphic a Title and enter the numbers for the Width and Height of the top graphic you designed.
Now in Background Image enter the URL of your graphic, e.g. http://www.mylittlemingle.com/wp-content/uploads/top-graphic.png
Now click Save Top Graphic.
That’s the top graphic sorted. You can come back and learn what all the other stuff is about later. If you click Override or Edit to the right of Default Top Graphic you’ll get an idea of what the Content area can be used for.
2. Define a page header.
Appearance > Design Settings, under Page Headers click on Add new Header. Give your page header a Title.
Set ‘Top sidebar’ to Header Widget Area.
Set ‘Primary content’ to be the top graphic we have just defined and saved.
Set ‘Showcase background’ to ‘No container’.
Click Save Header.
That’s the page header sorted. Again, you can come back and learn what all the other stuff is about later. If you click Override or Edit to the right of Home Page Header you’ll get an idea of what the ‘Showcase content’ area can be used for.
3. Deploy.
When you create or edit a page/post, in the Layout Options panel set Custom Header to be the page header we just defined and saved, and then click Publish / Update.
Fin, as they say in all the best foreign movies.