modify header in tweny ten

Hello all. I have done a search and so far I have come up empty so I thought I would post. I am new to WordPress and I am using the twenty ten theme. I attempted to modify my header today but the header stayed the same on the home page. When I click a link to a specific post, I see the header that I changed it too. How do I modify the header so that it changes on the home page of my blog as well? If someone else has asked this and I missed it I’m sorry…Thanks in advance for any advice.