The Qick Guide to successful children's parties
The Quick version of The Complete Children's Party Survival Guide

Parents

Avoid inviting all the parents to stay.
 
 
Avoid inviting parents of shy children to stay.
Avoid inviting any parents to stay.
 
 
Have a maximum of two or three adults (including yourself) supervising. Preferably none of the helpers (apart from yourself) should be parents of any guests.
     
If parent and guest turn up too early and you are not ready, suggest that they call back at party time.
 
 
Never feel obliged to take on extra guests.

 

For more detailed information on the above points see Chapter 4 & Chapter 5 of:
IntroInvitations