label each box with the room it's supposed to go into
Many hands make light work (get some buddies to help you out)
Pack your mattresses and large furniture at the back (stacking if necessary)
Cover wood finish with sheets/bedding to protect it.
pack extra clothing in Garbage bags and use them to cushion furniture etc.
Buy rubber maid containers instead of cardboard boxes. They're reusable and stack easier with more stability.