Hi and welcome to YT
! Can't wait to hear more about your soon-to-be new baby.
As far as size concerns -- the main thing to know there is that yorkie puppies are more vulnerable due to their small size - ie, being dropped, stepped on etcetera. Some of us will put a bell on their collar when they're puppies -- just remember DO NOT leave them alone w/ a collar on at first as puppies, as they could get it caught in their mouth from fighting the new collar or whatnot. Only put the collar on when home. Also, you never want to use a collar for walking a yorkie -- only a harness.
With working full time, you may want to try to come home at lunch time when you can for the first couple months. Otherwise, I'd free feed if you feel safe doing that - bc he'll need to eat about 4x per day at first.
As far as congenital issues, be sure to research the issues of the parents and grandparents, that's the most important thing. AND and and -- get insurance RIGHT AWAY on your puppy before any pre-existing conditions occur - AND make sure you have it on the puppy's medical records that the knees were checked and don't have LP (luxating patella). That way, should it develop later, the surgery would be covered by insurance.
As far as what to have for the pup, I'd start here:
http://www.yorkietalk.com/forums/pup...w-parents.html
My 3 kiddos are pad trained, but I sure wish I would've done outside pee training only. Too late now...