Thanks all! Here's what I have so far:
Paperwork:
Registration Papers
Health Record
Microchip Details & Registration Info.
How to care for your Yorkie Puppy & Yorkie Info
Eukanuba SB Puppy Sample (what they'll be eating)
4.5oz NutraCal
Fun Stuff:
Custom Birth Certificate (will put their paw prints on it)
Bow for girls
Bandana for boys (husband won't let me bow boys!

)
Snuggly Blankie from their bed
CD of Images of puppy since birth
How's that so far?