If I'm honest ... no! lol ... I have no tutorials or links that I have used etc ... however I may be putting a tutorial together soon on TwistedIllustration.com ... but it depends how much time I have. I learned by doing my own thing. I didn't follow any tutorials or anyone else's style. So if they are skilled, the best they can do is to just practice and play with the tools in Photoshop or Illustrator etc.
They're not gonna take my business are they? ;) lol ! Hope they have fun anyways... it's always got to be fun.