You know you are going to put your house on the market, so........

Gather packaging supplies, such as tape, boxes, and wrapping papers or plastics.  Use stickers or red markers to flag fragile packages.  Begin to pack up unused items that you plan to keep (donate unneeded items to local charity or have a garage sale to elimate moving unwanted boxes).  Label each box's contents and store them in a safe but out of the way location where they won't interfere with showings. Start keeping track of all moving expenses, because some might be tax deductible!