I want to, first and foremost, say I am so sorry for your loss!
I have a small piece of advice for you. I think the most common mistake that new dog owners make when taking in either a rescue dog or a dog from a situation such as yours... is that they tend to completely dote on the dog, give lots of affection and love and "feel sorry" for the dog. But I highly believe that dogs do not live in the past, or the future, but in the now/present. Yes, dogs grieve and it will take time. But I wouldn't dwell on it. He is going to have a great life with you! If you haven't got him yet, the first thing I would do when you get him... take him on a nice walk, just you and him and establish yourself as his "leader", his new friend, his new owner .... okay, I'm sounding incredibly repetitive of the Dog Whisperer (National Geographic Channel). I think I watch his show too much.
But his main "guideline" you could say is Exercise, Discipline, Affection, in that order and I truly believe in that. If you follow that, you're one step above most dog owners in America! Small dogs often get "small dog syndrome" because they're tiny and cute and people let them get away with things. Anything you wouldn't let your GSD do, don't let your Yorkie do either
Hmm, as for
Is there anything special I should know when it comes to training or feeding when it comes to Yorkies? Yorkies are prone to tracheal collapse and should only be walked in a harness, NOT a collar. I didn't know of this until joining this site. Some Yorkies have sensitive stomachs it seems like, but of course not all. Yorkies are true terriers (well, most of them, not all of course!) and are not always the little lap dogs people perceive them to be. They still need exercise and need to burn off their energy.
I wish you the best and hope to see ya around here!