Looking for a tutorial..or just plain old help!!!

I am trying to build a child theme using the thematic framework and I am a little bit stumped when it comes to swapping out the header…I have designed and built a header using HTML and CSS in Dreamweaver but when i drop the code into header.php and the stylesheet it doesnt work…just stays blank as if the code is broken or incomplete…( which i am sure it is)

so I guess my question is where can i go to learn about how to insert my custom header code?

Thanks,

Al