I think everyone has given you good advise on the food as I have such a gang with different issues I will only give you the brands I use: Innova, Nutro, Nature's Variety (raw) and Nature's Balance.
Treats are Charlie Bears which can be found at Pet Smart
and for Shampoo I use Coathandlers Shampoo and Conditioner. I love this shampoo as you can use it right on their eyes and it doesn't hurt. This shampoo was created by a Yorkie Breeder and it really makes a difference with their coats.
www.petedge.com and other internet companies offer this product.