Here is a link I found very informative last year.
http://www.disboards.com/showthread.php?t=2504773
It still has the dates for 2010 listed at the top but scroll down and you will find lots of info! Have a great time!
Okay, I am not sure if that is a clickable link. If not, go to the top of this page and click on the "EVENTS" tab, then "Halloween", then "Mickey's Not So Scary Party" and then, finally, after the dates are listed, it says Mickey's Not So Scary Party links.... click on the last link that says"Tips and Tricks to enjoy the party"!