Unity Editor API docs and tutorials

Anyone can point to some good resources for Unity Editor API customization/programming ?
Thanks.

http://unity3d.com/support/documentation/Components/gui-ExtendingEditor.html

http://unity3d.com/support/documentation/ScriptReference/20classhierarchy.Editor_Classes.html

*edit(examples as requested): http://www.unifycommunity.com/wiki/index.php?title=Scripts#Editor_Scripts