The header of your site is typically the first thing people see.What is across the top of your page is what people make judgements about what they are about to see and read. Research suggests that you only have 30 seconds to make a good impression when someone lands on your site..
The WordPress Header
By default, the WordPress header is a simple piece of code. You do not have to get into the code to change the header that comes with whatever WordPress Theme you choose. You set the blog or website title and description in the Admin > Options panel, and WordPress does the rest.
The header of the Default/Kubrick Theme
Styling the Header
As listed in the two above examples, the styles for the header are contained within the h1, header, headerimg, and description CSS selectors. These are all found within the style.css, though may be found in the styles in the header.php of the Theme you are using. You will have to check both places.
In the Classic Theme, the CSS for the header are found in one selector, the #header.
#header {
background: #90a090;
border-bottom: double 3px #aba;
border-left: solid 1px #9a9;
border-right: solid 1px #565;
border-top: solid 1px #9a9;
font: italic normal 230% 'Times New Roman', Times, serif;
letter-spacing: 0.2em;
margin: 0;
padding: 15px 10px 15px 60px;
} The background color is set to a green shade and there is a border all the way around the header which changes colors creating a recessed, shadow effect. The Times font is set with a size of 230% with a wider than normal letter spacing. The padding on the left side indents the text in from the left.
All of these can be easily changed, giving the border a thicker width and making it all the same color, changing the background color, the font size and style, the letter spacing, and more by modifying the information in each style attribute.
The same is true of the Default WordPress Theme header, except there are more styles to think about and they are found within the header.php's "head" tag and the style.css, though once you have your styles set, you can move the information into your style sheet.
The styles that control the header's look are found within the h1, header, headerimg, and description CSS selectors. Just like the Classic Theme, find these references and make your modifications there to change the look.
Changing the Header Image
There are many different header images and header art available for you to use to change the image in the header. The styles for the header image for the Default or Kubrick WordPress Theme, and any Theme based upon that Theme, are more complicated to change than those for the Classic Theme. The styles are found within the styles in the header.php "head" section, as well as in the styles.css. To change only the header image reference, open the header.php template file and look for the styles like this:
#header {
background: url("/images/wc_header.jpg")
no-repeat bottom center; }
#headerimg {
margin: 7px 9px 0;
height: 192px;
width: 740px; }
To change the image file, replace the "kubrickheader.jpg" with the name of the new graphic image you have uploaded to your site to replace it. If it is in a different directory, change that by replacing the bloginfo() tag with the specific address of the graphic's location.
If you are using an image that is the same size, then simply replace the image. If it is a different size, fill in the height and width of the image in the next section called #headerimg. If you do not know, and are using Windows, view the folder in which the image resides on your computer in Thumbnail view mode. Click View > Thumbnail from the Windows Explorer menu. In Thumbnail view mode, find your image and hold the mouse over it. A small balloon tip will pop up listing the dimensions. Use that information in the styles. Otherwise, just right click on the image file and choose Properties and it should give you the file size and dimensions.
Header Image Specifications
A header image that fits within the Default WordPress Theme is about 192 x 740 pixels. If you are replacing the header within any WordPress Theme, check the size of the header image and then find a replacement that matches that size. If you choose a header image that is smaller or wider or taller than the replacement, you may have to modify the other structural elements of the web page to allow for the change in size of the header.
If you set your website to "float," positioned in the middle of the browser window with space on either side, then you can set your header width to whatever you want. If you are designing a Theme with a flexible or "elastic" screen width, then the width of your header becomes important.
If you are using a header image that can be repeated, and you are using elastic widths, you can set the styles within the header to repeat to fill the space:
#header {
background: url("/images/kubrickheader.jpg")
repeat-x top left; } Hiding the Header Text
Many Themes and Theme designers want to feature their header with a picture only, no text. Some will put the text in the graphic image, therefore not requiring the actual use of the text. One option is to remove the template tags that generate the title and description. The other option is to leave it in, but hide it.
Header Tips from WordPress
You can change the look of your blog with 
Built-in rich text editor makes it easy to create great looking posts. You can upload your own photos or easily include images from other services like Flickr or Photobucket. You can even embed videos from places like YouTube or Google. To keep you from looking too silly, we include an inline spell-checker that makes it easy to proof your posts. We also have a preview feature that shows you exactly what your post or page will look like before you publish them for the world to see. Finally we know how frustrating it can be to lose hours of hard work, so every minute when you’re writing a post we save it to the server to keep your post safe in case your computer crashes or something else happens.
