These books are excellent sources Other Books that may be helpful. If you get dehydrated thats bad news and it takes a lot of the fun out of the hike. I figure 8oz. If you feel thirsty its already too late. Pound some before leaving camp.
Water is everything.
Cheese, granola, rice cake ,oatmeal bars. Have a good hearty breakfast of hot oatmeal. Bagels on the way are nice. This will prevent a burnt nose and ears. Extra shoelaces, tweezers, first aid cream.