Outfits 
Undershirts
hat for newborns
Diapers
Wipes
A&D butt cream
desotin butt cream for rashes
cottonballs
baby oil
diaper bag
bottles
formula
bottle thermos
portable bottle warmer if no kitchen facilities
bath soap and little plastic bowl to put water in during a bath
bath tub for extended visits
wash cloth
socks
stroller and car seat
gas drops (not after 6 months)
gripe water for newborns
benadryl
tylenol
Dreft laundry detergent for babies
thermometer
burp cloths (not after 6 months)
blanket
more pacifiers than you think you need (at least 3) and thing to attach it to baby
plastic bags to put dirty diapers into
bibs
bottle brush
rain, sun and windshield for a stroller
sunscreen and hat
feeding spoon or fork and spoon as age requires
baby food
toys and books / favorite teddy bear, if applicable
prune juice in case of constipation
some cheerios or snack and a cup to hold the cheerios
hair brush
shoes
2 sippy cups
first aid supplies
extra zip loc bags for food storage
kids' passports
car music CD's
DVD's, player, charger and headphone
baby monitor
crib bumper
infant car seat