Belly band is a Great start. Some of our YTers sell some cute ones.
I trained Zander by taking him outside to tinkle 1st thing in the morning, as he is peeing OUTside, I would say Good boy Pipi, immediately give him a treat, I chose cheerios, I would play with him for 20 minutes, then put him in the crate, take him out, play crate. I read all I could about Potty training, with crate and other ways. While he is Not potty trained HE should not have the run of the house. When he picks on your other furbaby, tell your yorkie, NO, then put him in his crate or time out. Watch Cesar Milan dog whisperer, online or on tv. he is great, I also like the lady from It's me Or the Dog.
You have to show your dog, discipline, boundaries, you Will be so proud and happy of your Good boy, arm yourself with knowledge and help Your Cutie be the best lil Furboy.