Every so often people ask me about the best places to start learning icon design. I've gone through my bookmarks to collect some of my favorite icon-design related resources below.

Process Videos:

• Milky, Nyanko Sensei [Pedja Rusic]
• ComicBunch, Rocketter, Subway Trash Can [Nikolay Verin]
• Valentine's Icon [Cuberto]

Designer Blogs:

• About App Icons, Icon Sizes, Icon Metaphors [Louie Mantia]
  
• Many Mirrors, The Versions Icon, Iconic [Jasper Hauser, Hugo van Heuven]
• The Interarchy Icons, Here, Icon, Icon [Sebastiaan de With]
• Icons and Logos are NOT the same [Michael Flarup]
• Icon Design Process Presentation [John Hicks]
• 10 Mistakes in Icon Design [Turbomilk]

Designer Interviews:

• Laurent Baumann
• Jonas Rask
• David Lanham
• Pedja, Kajdax, Prekesh, Asher

Apple:

• macOS Icon Design Guidelines
  Apple's icon guidelines contain a lot of the basic information about how to make a good icon.
• Application Icons [Need a Mac]
  To view an Application's icon in full resolution, right click on the app in Finder and select "Show Package Contents". Then open the Contents/Resources folder and look around for a file with the extension .icns. That's the icon file. You can use Quicklook [Spacebar] to view the full size only, or open it in Preview to see all of the different sizes.
• Coretypes.bundle [Need a Mac]
  Most system icons are stored in /System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/. You can either navigate here by hand, or use ⌘ + Shift + G to bring up the Go To Folder window and paste the above path into the input field.

Inspiration:

• Dribbble
• Mac Icon Gallery

Send me a mention on twitter if you've got a resource you like but I've left out!