Luggage and bags:
Take a slow friend - that way the bears will catch them while you run away
Clothing/Shoes/Weather Gear: Arctic gear for the winter months, pack a hat for the summer
Toiletries and Medical Supplies: Bug Spray is a must in the summer.
Miscellaneous: Food and water - keep in mind there are lots of opportunities to get stuck or stranded. Take plenty of food and water.
Clothing/Shoes/Weather Gear: Don't forget some good sunglasses! The sun stays at a low angle for many month (when it come up at all)