If you'll be flying, be sure to get your tickets ahead of time. Also be sure to rent your moving van, if applicable, and calculate if you'll need to stay overnight in any hotels. Contact your local utility and phone companies- Let them know about shut off dates. Also contact the companies near your new residence, so that you won't be without electricity, heat, and water after you've made your long trip. You're bound to need more than they have, so contact your local discount store and ask if you can have boxes from their freight.
Most discount stores receive daily merchandise and destroy the packaging and boxes after unloading.
Try to take lots of smaller boxes to avoid over packing boxes, causing them to become to heavy. While you're at the discount stores picking up the boxes, purchase bubble wrap, boxing tape, and large black markers. Whether it's a written plan or one in your mind makes no difference. The point is to have a plan of attack. Decide which room to start off in.