Welcome to YT!! Don't know of any Yorkie breeding sites or books, but we used Debbie Jensons site its
www.debbiejensons.com she has a wealth of information. She breeds shzi tzu's (I know I didn't spell correctly),lol, Try this site and just apply most of what she says to Yorkies. Her site helped us when Dori was in heat and whelping along with some valuable members/breeders here on YT....Good luck
