Definitely google/youtube videos about this! They have yorkie specific videos for every stage of grooming that you'd ever dream of! Even just for the usual, in between, maintenance it's a lifesaver!
They'll also show you what tools you'll need and how to use them. The biggest key to grooming them is being confident about it. They will sense your unease and it'll make them nervous as well.
Even if you have no idea what you're doing, just do it confidently
LOL