1. Water! Water! Water! Can't live without it, at least not very long. The great advantage to stored water is that you can rely on it to be suitable for drinking. The amount recommended for drinking, food preparation, and other limited uses such as brushing teeth, washing hands and dishes, is three gallons per person for the 72 hours. If the warer purity is questionable, take along some means of purifying it. There are lots of choices for purification. Iodine, bleach, boiling are just a few. The EPA has a good explanation of purification. I have used juice bottles and soda bottles for my storage. You have to be pretty careful with reusing bottles. Make sure they are super, super clean. I have opened bottles that smell awful. You can add two drops of bleach when you fill the bottles and be sure they are clean but a warning...too much can kill you. Do not use: milk jugs, jars that have held alkali or acid based products, and containers that held food food, like mustard, ketchup etc. There are great places to pick up water containers. Walton Feed has them, Emergency Essentials does also.
2. Cooking utensils and supplies: Since in month one and two you put your food in your containers, now you need to add any items you might need to prepare it. You can include pots, utility knife, can opener, mixing bowl with a lid, wooden or metal spoons, container for mixing drinks, cleaning supplies like soap, scrubber, towel, and a stove if you need to heat water. Many of these items are easily accesible at thrift stores or garage sales. We have a little thing that fits together with one can of propane. Its enough to heat water for our oats and hot chocolate. I might add to this but for now it is sufficient for us. Look at what you have and gather your supplies.