Hi,
We took our little girl to USA when she was Ten months old...not quite walking, but definently crawling.
I found that having a basinet seat helped a lot with free hands time, so you could eat a meal and put them down to sleep since a baby is usually strapped to you the whole time if you dont have a seat for it. It was recommended that we get something to help her sleep, but we decided against that, as she is normally a pretty adaptable child, so LUCKY for us, it didn't seem to worry her.
Coming home , we had more leg room,but no basinet (she was past the age limit) , that made things a little more difficult, but it was still not too bad, the airline seated us in a empty row so that we could have more room.
We pretty much stuck to the same routine we have at home with her eating and such, just making sure that she was sucking for take offs and landings (of which she fell asleep on all occasions) coming back to Australia she slept for about 8 hours, so that wasn't too bad.
I am a nervous flyer myself, so this was a real test for me. The staff of our airline were fantastic and made us feel very welcome, and other passengers usually understanding, one commented to us that all the children were very good on the flight, which was a relief as ours cried for about a hour, not too bad for 28hours of travelling though, which involved , cars, planes, buses and trains!
Hope you have a great time!!!!!