Below is a link about DCC that you can download to your PC for further viewing. This fellow use to own a very good DCC online business until he retired. He is works closely with the new owners.
You can ignore the part about using a computer with DCC if that is not your thing.
http://issuu.com/mr-hobbyist/docs/mrh11-10-oct2011-ol/50?viewMode=presentation&mode=embed
Rich