I've been hunting for a decent tutorial on how to make colour images for ages. Seems to me there's tonnes of images in various databases around on the net that anyone can access.
Anyway I've happened on this tutorial here: http://lcogt.net/education/article/h...ages-photoshop
Which is well illustrated with a youtube video. The guy uses photoshop elements which is a significantly cheaper version of photoshop. They use it at work for photography courses so it must be up to scratch.