Welcome again, and congrats on finding your new fur kid. You simply must post pictures when you bring her home. What name did you pick?
I've been doing my own grooming for over 50 years and have found for my four Yorkie girls that a pen brush that has the molded round tips, and not those that are added on, are best no matter the brand. I bought all of mine at Wal-Mart. Then you will need a pin brush to get the mats out if your girl gets them. A little comb with teeth that are close together, for the face and under the eye, and please, don't cut the hair around the eyes. Brush out once a day and look her over for anything that may be on her, like briar's and such.
There are more good shampoo's on the market than I can list. Just make sure you get one that you can do frequent shampooing without stripping the coat. I buy #1All Systems. It's very concentrated and you mix with 7 parts water, so it goes a very, very long way and is ideal for frequent bathing. I use their conditioner as well. In the winter months, I use Vegetable glycerine, heated and give them hot oil treatments. Vegetable Glycerine is the only oil that actually penetrates skin and hair. It rinses out beautifully and never oily. After I rinse out, I use the conditioner.
Have the Vet. show you how to cut the nails. You will also need an ear drying solution for after the bath, and eye rinse. These babies are so close to the ground, they get lots of dust in those little eyes that can cause a lot of tearing and problems.
I could go on and on and on, but your eyes would be going around in circles. If I can help you any further, just ask. We all love to help new Yorkie owners, so your going to get great advice from the parents here.