This tutorial shows how to add a background to an image and incorporates layering and simple painting techniques. It's probably on the beginner's side of intermediate Photoshop work, but when I put it together, my mind said that it should be labeled as intermediate. Beginners, don't be afraid to give it a try!
Below are the resources that I use in the tutorial, along with some other useful links. The Photoshop brushes are not freebies, but I'm not trying to convince you to buy them either. I just find them quite useful and since they're what I used here, interested parties might as well know where to find them.
Ron's Steam and Smoke
Creating an Orton Effect in Photoshop
Michael Orton: The Orton Effect
This tutorial can also be viewed on my Deviant Art page.