Trying to change the Favicon and had a few questions.

What type of graphic should I be using (ie; PNG, GIF, JPG)?

What size should this graphic be?

If I have a "drop-in Template" do I have to edit the css file and if so what would the cammand be?
or can I just set the icon from the Admin menu?

Thanks in advamce for all your help.....

To try to ensure compatibility with everything, I recommend using ICO format only.

This website generates Icons that I know work with most browsers

http://www.rw-designer.com/online_icon_maker.php

Firefox can handle PNG, GIF, and JPEG just fine, but IE doesn't. ICO is your only way for full cross platform compatibility.