I use Buddy Splas from Cloud Star to dampen the coat - great product filled with herbs & natural conditioners. I also believe in investing in a good pin brush & comb. I love the chris christensen 20mm gold pin brush.
yes, do not brush a dry coat, you may not realize the damage you are doing to the coat. I think the think about combing out the coat, is not to do it when your dog is immediately from the tub, as you can stretch the hair, causing damage.
go about 1/2 way down the page for some great info:
http://www.chrissystems.com/grooming.htm
This is great too -
http://www.ytca.org/grooming.html
Mandee, this one even addressed different types of yorkie coats
http://members.cox.net/jrogan/care.html
one last good site:
http://crownroyalyorkies.com/basic_grooming.htm