Upload header image

Q: what css code would I use to add a header image with the new template designer?
A:Header image
You do not need CSS codes for that.

Save image to your desk top (image 1).

design>>edit (header)>>configure header

Check [shrink to fit], 

Choose file from your desktop (image 1)

Open

Wait for upload

Save.

Here is a tutorial: http://www.youtube.com/BloggerHelp#p/u/1/jTX3EsUVjuc

source:http://www.google.com/support/forum/p/blogger/thread?tid=2a22657b9196d676&hl=en&fid=2a22657b9196d67600049ae287c1da60