This tutorial is an oldie but very goodie by maclean (I assume the maker of the Interiors Classroom and Room Creator and other excellent things), which is recommended on a Daz forum for beginners.
I made a video of it using Camtasia Studio 7 for my own convenience, which maybe others will find useful. It is only 3 minutes or so long, and you will need to pause the video at the interesting bits (it’s really like a movie of a slideshow).
It deals with an early version of Daz, but it is still a useful and clear explanation of cameras, lights, DOF,shadows and clever composition for beginners and thickos such as myself.
Hope you fnd it useful.