Here are a couple of buttons you can add to your blog or website, as I have done on the right here. On blogger, just login to your blog, go to the layout and add a picture gadget. For the link, put http://www.onemillioncampaign.org/ and add a suitable extra message if you want.
There is also a banner advertisement that you can add to your site. Here is how it looks on the Baby Milk Action site:
To add the banner, simply follow the instructions you find at:
You will find other resources in the aptly named 'resources' section of the site. Also see other blog entries here tagged "ONE MILLION CAMPAIGN".