You can add a custom favicon from the Design | Page Elements tab (or, from the Layout tab if you're using the new user interface), by clicking Edit on the new “Favicon” setting above the navbar element:
A new window will then open where you can select an image from your hard drive to replace the default favicon image. This initial launch only supports .ico files, but you can easily convert your JPEG, PNG, or other non-ico image file using your own image software. There are also many conversion tools online, and a quick Google Search brings up a handful of options such as http://www.icoconverter.com/.
Once you’ve selected the .ico file for your favicon, click Save. Blogger will automatically resize the image to the correct dimensions, and you’ll then see the Page Elements updated with your selected favicon image:
When you save your template changes, you’ll see your newly-added favicon image displayed in your browser window or tab. That’s it!
