How long are you traveling for? Where are you going? Will you be in a hotel? I can give you loads of tips, just need a little more info. We are military and have moved 4 times and lived overseas with little ones for years.
I took my five and a half month old daughter with us overseas. Have your flights scheduled during sleep times---overnight and during nap times. Are you buying a seat for her or will she be a lap baby? Bring more diapers and clothes changes along than you think that you'll need! I used my sling on the plane while walking back and forth down the aisles.