Learning HTML

Thought about changing the way my blog looks. First step, change the banner. How ? No Idea. Then came across Cut\Copy, Paste Blog. It was a huge help & it suggested flickr site where anyone can register & upload their images which they can use in their blogs. It automatically creates the html code for the uploaded images.
So the experiments are in process. If the layout annoy U, my sincere apologies. And any suggestions are most welcome.