Favicons are those little images that come up in the URL bar to the left of the URL in your web browser. They are also displayed on the browser tab if you’re using Firefox. Here’s how to make em’ (this is the “very quick” version). See Steve Cooley’s Site for a more detailed version.
1) Choose you image and resize it to 16 by 16 pixels. (Use an image manipulation program of your choice – Photoshop, Iphoto, Gimp etc. ) You’ll want an image that is not too complex as the larger image may look good at full resolution but when it’s resized down to the size of a postage stamp it’ll probably look like shite! Choosing an image or piece of line art that’ll look good the 16×16 resolution is probably the hardest part of the whole process!
2) Download IcoMaker from this link. It’s free and will convert your image from jpg (and other image formats I believe) to the .ico format.
3) With IcoMaker launched select File > New Document. A little multi-pane window will open. Next import your image into IcoMaker by doing a File > Include Image. Choose a 16 x16 copy.
4) Save the file as favicon.ico and upload it into the root directory of your website!
There you have it, happy Faviconing!