Brian, the big thing in my book is a good venue, plenty of parking (for the show cars) plus the visitors. And something else to do/look at besides the cars, kids games, food, vendors, etc. Having a low entry fee and asking for donations is better IMO that asking for a big ticket up front. I have been to plenty of too small/poorly run events
I keep a google calendar maintained for most of the central NJ shows/cruise nights, with some specials from North and South. Scott knows the URL, its public.
Luck!