If you like the Lords of the Rings movie trilogy, then you might also like this Photoshop tutorial, where we will make a dramatically red sky on a random photograph.
Pretty simple and useful tutorial, where you will open a random photograph with smoke and convert it into something really not friendly for our environment.
A simple Photoshop tutorial, where you may learn how to expose an object by leaving it in color while turning the rest of the photo black and white or sepia.