Built to Scale
Icons come in many shapes and sizes; from glyphic pictograms to elaborate ‘realistic’ HIG-compliant OS X and Windows icons, Icon Resource covers sketching them out, modeling them in just Photoshop or similarly featured software, and ensuring they kick ass at all intended sizes – including fitting them into cramped spaces.

Theoretically Academic
Icon Resource doesn’t just let you figure out the design methods and step-by-steps for pretty pictures, it also tells you a bit about the background of icon design, the guidelines you have to adhere on various platforms, and teaches you common pitfalls so you can prevent those nasty ‘redesign situations’.

More info: http://iconresource.net/Desktop/