Since I am in the thick of moving right now, here are some of the things I am doing to try to keep sane:
List It Out: Jot down a list of every little thing you need to get done from now till move in day. Get it all out of your head and down on paper. Then, each morning, move part of that list into your daily "to do" and start tackling.
Start Early: Try packing a few boxes each night for the entire month. This way it won't be so overwhelming at the end to get it all done at once.
Make Your Calls All Together: Set aside one hour to just continuously call each utility, each credit card, each physician, each online account, etc., and update your address. Just rip off the band-aid all at once and it'll be over before you know it.
Purge: Have "give away", "toss" and "sell" boxes tucked in the corner to fill as you pack. Getting rid of your extra weight now is going to make your move a lot easier, and cheaper if you are paying movers.
Color Coordinate: Choose a color for each room and mark each box accordingly.
Organize: Label each of your boxes with what room it will go in and what's inside. This will help the boxes get to their correct destination and save you endless hours of rummaging through boxes over and over trying to find your cell phone cord, etc.
Stay Calm: It is very easy to get out of control and overwhelmed when you are faced with so much to do in such little time. So remember to breathe, and just keep telling yourself that you have done this before (assuming you have) and have gotten through it each time. Once you are settled in your new home, kicking back and drinking your inagural glass of wine, you'll forget all about how much of a pain it was to get there.