I have watched some Blogger videos to see a way to change the header by selecting an image and manipulationg it in photoshop. The image is cropped, resized and has text added and layered over it. It is exported,saved, then selected in "browse" and replaced as the header in blogger. Very cool. I followed the steps and went in to HTML to see the "outer wrapper" pixel size, went in to my photos and experimented but the photo always came out too large for the blog. I can see the problem lies in finding out the exact dimensions of my original saved picture and manipulating it. More experimenting to come...