Hello Diane,
Linda's right, it depends on the theme you're using. (Feel free to post the theme name and I'll let you know what you need to do.)
To change your header, generally there is a file called 'header.jpg' somewhere in the theme's image folder. You need to find that file, its dimensions, and replace it with your own custom file.
If you want a decorative title for your blog, that would require a little more tweaking. It would involve adding your blog's name to your new header using a graphics program, such as Photoshop, and modifying the CSS so the default blog title doesn't show up over it.
Otherwise, follow Linda's instructions and you can change your blog's name from the admin panel.
Hope that helps out and if you have any specific questions about WordPress, please ask, I'm sure that (if not me) there are plenty of people here who are willing to help out.
~ Teli
|