Depends how techy you are.
I have POIs of many sites, CC sites, aires, motorhome stopovers etc. I spent hours downloading various POIs for campsites etc.
If you know how to install them I can email them to you. They are in OV.2 format so suitable for tomtoms.
Tom tom are brining out a dedicated camping satnav soon ( i posted elsewhere on the forum) but will probably cost a fortune.
Another great solution is this website that works best on a iphone but also works on(some) laptops. The POIs are stored online and if you have satnav on you smartphone you simply navigate to them.
Caravan club and other campsite pois are found under association.