Hi and Welcome to YT!
Here are some links that may help:
Puppy Care and Puppy Info Library - YorkieTalk.com Forums - Yorkshire Terrier Community
And OMGosh is he a cutie!
Be extremely careful with office type rolling chairs... Yorkies like to lay under them and they can get badly hurt if you roll the chair back over them. When I sit in mine, I have a habit of turning the seat around so I can see clearly under it where mine are, before I even attempt to move the chair or even get up.