Under-armour under clothes.
Gore-tex: camouflage fluorescent orange coat, gloves, hat, pants, and boots. For the gloves look for hunting mittens, they have all four fingers in one area, and a flap to slip you fingers through to work the gun. Get the fluorescent orange base color that also has pasterns of branches and leaves. Deer are color blind and do not see the fluorescent orange. Most states have a requirement of a minimum amount of fluorescent orange you have to wear.
Gore-tex is great stuff. You can be out in a cold rain and remain dry and warm, and it breathes so it is harder to get over-heated in.
Hunting license (including permit for the county you will be hunting in if required, some states have a limited number of permits per county and you have to apply to a lottery and win a spot to allow you to hunt there) and a holder to display the license on you back or hat depending on requirement. If you do not properly display the license and county permit if required, you can be fined. Most states have a tag you fill out and remove from you hunting license and attach by string or wire tie to the ear of the deer. You have to do this before you move the deer, and you should do it before you gut it. Be certain to attach it well, like through a hole in the ear of the deer. They are easy to loose when you drag the deer out.
If you get a deer let it lay for a while before you approach it so it has time to die. Then when you approach it consider it to still be alive until you use the front of your gun, or end of your bow to poke it in the eye to see if it is dead.
My dad worked with a guy who had a son who approached a buck he had shot. The buck got up and gored the young man with its antlers. He got cut on the inside of his leg by the groin. It hit an artery. There was no areas above the cut to stop the bleeding and he bleed to death. So remember to let it have time to die, and then be sure to poke it in the eye to see that it does not move.
GPS unit that you know how to use, and spare batteries. If you are not familiar with GPS get one in advance and learn how to use it. Before you leave the vehicle to walk into the woods, note the location of the vehicle you will want to return to. You might write down the coordinates of the vehicle if the GPS unit will lose it when changing batteries.
If you can't afford a GPS then get a Compass: take a reading of the direction you are going when you leave the vehicle and walk into the woods. If you might forget that reading write it down. Note any major changes in direction when you walk in. You will have to back track these directions by 180 degrees to get back to the vehicle.
The last thing you want to do is get lost. If you are hunting with a group, do not count on the group to prevent you from being lost. I have been in a hunting party of five and we all met up, but had a heck of a time finding the vehicle we came in.
Wet-Fire fire starter. I do not know if you can take a Bic butane lighter on an airplane so after you get there pick up a Bic butane lighter at a restaurant or convinced store.
Canteen, cereal grain bars (I like SnackWell's Cinnamon Raisin).
Toilet Paper, also good to help start a fire.
Do not count on your cell phone in the woods, there is a very good chance it will not be close enough to a tower to allow it to work. If you want a cell phone that will work in the woods you will require a satellite phone (you can rent them).
Hunting knife to gut the animal.
For deer, you will require a rope to drag the animal out of the woods. If you carry a deer you risk getting shot.
Very lite weight emergency survival tent (the one time emergency use kind that fit in a large pocket). Lite weight sleeping bag.
A back-pack to put it all in.
Small chemical flame-less heaters that you open and expose to air to activate.
LED flashlight. (get one that uses the same size batteries as the spare batteries for the GPS unit if you get the GPS).
In big game country, most hunters carry a large caliber pistol just in case a bear happens to ketch you without your rifle.
Another story: A friend of my dads was in the garden of the camp and did not have his rifle with him. A deer came by and he took it with his pistol, but he tried to conceal the pistol from the deer by keeping the hand not holding the pistol in front of the pistol with his hand forming a opening for the bullet to pass through. He got the deer, but the flash burned the heck out of his hand.
Drinking and hunting do not mix. You can be fined if you have a couple and then hunt. Wait till the hunting for the day is over before hoisting a few.