Editing digital photographs - compositing

ARS Technica published the third part of their digital image editing guides, this one focuses on compositing:

"Composite" is just a ten-dollar word for a combination of images and here we'll be covering how to combine one or more photos for convincing results. If you're brand new to digital imaging and don't know say, the definition of "digital" or "imaging," then I suggest a little more reading on the subject before jumping head first into this tutorial. It's written assuming you've got a basic understanding of level adjustments, curves, selection by color, feathering and layer masks since that's what we covered in the first two articles here and here.

You can check it out over here.