A Surprise Party is something that should start being organized at least a year in advance. My tips for getting a Surprise Party started are:
*Only let 2 (Maybe 3) people in on the secret. The more that know before the invites are out the more chance the VIP will find out.
*Choose and book your venue as soon as a date is selected. This will allow for easy organization for decorations, layouts and a place to store everything if possible.
*Choose a theme that describes the VIP. Like their favorite colour, decade, TV Show or movie.
*Keep a note book just for the party and write down every phone call, inquiry and guest. Make a "Final List" in the back so you know exactly what you have booked for the event.
One thing that seems to be a necessity these days is having a "Social Media Ban" on anything to do with party. No RSVP's over facebook or status updates saying you are going. Try and find a way to put that in the invite somewhere.