These sites save your image (whether made or original pic) into ico format
Favicon Generator Gallery
*IF YOU ARE UNSURE WHAT TO USE AS YOUR PERSONAL FAVICON OR YOU ARE NOT THAT COMPUTER SAVVY THIS IS WHERE ICONS ARE HELPFUL.
Icons are the perfect size for favicons and we just happened to feature a bunch of different ones on one of our "Download Days". If you are still unsure about what to use, our suggestion is just your initials or company initials/simplified logo, since the size of favicon has to be small.
The following link is great step by step instruction on installing your personal favicon:
CREATE YOUR OWN FAVICON
You can use other free hosting services to host your custom favicon, but you don’t want to use an image hosting service that deletes images after so many days. Using Blogger.com to host the images works well, but you could also use Google Page Creator, or even your Flickr account.
WE SUGGEST NAMING THE IMAGE "FAVICON FILE" TO EASILY RECOGNIZE
Just remember that adding your personal favicon to blogger is a bit of a hack
Have fun adding your custom favicon to your Blogger.com blog!