This certainly isn't the most usable advice in the world, but the geek factor is huge and it's fun. Use Google Maps satellite imagery.
maps.google.com - there's plenty of open grass fields all over the place - and state parks are indicated in the hybrid mode. Find the zip code of the
area and goto weatherunderground.com and try and find historical wind info if it isn't near water (moot if you have 5 kites like some of these guys,
I'm sure). I haven't even gone out yet, but I found the first and second places I'm going to try that way.
Ozone Samurai 7.2m
MBS Comp 16 Pro