Resizing Images for the Web: Photoshop Tutorial
http://tiemdesign.com/HOWTO/2004/February/PSWebResize/default.asp

Photoshop Today
2004

Abstract:

We all have those photos that we like to on the web to share with our friends. Or, we have some terrific images we've created that need to be resized for the web. Images for the web need to be both small in file size and in physical dimensions so that our viewers don't have to scroll right to see the whole picture. In Photoshop we can adjust our huge images to fit the web quite easily.