Hi Shannon and congratulations on your new baby!! What's his name, size, etc. Inquiring Yorkie mommies want to know!! We all get excited at the prospect of a new baby!
Fasteddie had good advice. The way we started Toto out we learned from one of the many books we studied! If you keep him in a crate ... when he starts to cry, simply tap on the metal with another metal object [I used a little curtain rod]. Don't "whack" ... just lightly tap and they HATE that noise! It took about 6 times but Toto never barked at bedtime again!! She is one now and since we aren't "afraid" of her anymore we eventually let her start sleeping in our bed, but it was our idea and not hers! We just couldn't bear to be 2 feet away from her!!
Good luck!