I am wondering if someone can point in the right direction for learning how to write a plugin to customize the admin area. I need to add a new product type to the drop down list. When this item is selected and saved I need to show a new menu item. This is exactly what happens when bundled product type is selected.
Any help that someone can provide to learn this part of the system would be helpful. Both adding the new menu item and manipulating the product type list.